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The chromosome numbers of Anthyllis vulneraria subsp. balearica (2n=12), Cymbalaria fragilis (2n=56), and Polygonum romanum subsp. balearicum (2n=40) ...
Folia Geobotanica 41: 433–451, 2006

NEW CHROMOSOME NUMBERS FOR PLANT TAXA ENDEMIC TO THE BALEARIC ISLANDS Mercedes Castro1) & Josep A. Rosselló2*) 1) Facultad de Agronomia, Universidad Central de Venezuela, Apartado 4579, 2101 Maracay, Venezuela 2) Jardí Botànic, Universidad de Valencia, c/Quart 80, E-46008 Valencia, Spain; *) Corresponding author: fax +34 96 386 68 26, e-mail [email protected]

Abstract: Mitotic chromosome numbers are reported from 25 vascular plant taxa, endemic to the Balearic Islands that are poorly known cytogenetically. The chromosome numbers of Anthyllis vulneraria subsp. balearica (2n=12), Cymbalaria fragilis (2n=56), and Polygonum romanum subsp. balearicum (2n=40) were determined for the first time. A new chromosome number was found in several populations of Anthyllis hystrix (2n=70) suggesting that this species is decaploid, in contrast to an earlier work reporting a higher ploidy level (2n=12x=84). The new chromosome number 2n=32 was reported in Hypericum hircinum subsp. cambessedesii. It is suggested that the previous count (2n=40) could be explained by the presence of anomalous pentaploid cells in some tissues, contrasting with the presence of a regular tetraploid complement (2n=32). Cytogenetic observations suggest that Sibthorpia africana has a diploid chromosome complement of 2n=18, with 0–2 accessory chromosomes. Accessory chromosomes are also reported for Phlomis italica, being the first record of B chromosomes in this genus. Chromosomal instability was found in Galium crespianum and G. friedichii species, with three numbers 2n=44, 55 and 66. Two cytotypes differing in ploidy level were documented within single plants. It is suggested that both species share a regular complement of 2n=44 and that the past hybridization events and formation of regenerating roots from the typical rootstock of G. crespianum and G. friedrichii could be involved in the genesis of chromosome variants through partial endopolyploidy and concomitant somatic segregation. Keywords: Accessory chromosomes, Anthyllis, Cymbalaria, Galium, Hypericum, Polygonum

INTRODUCTION

The flora of the Balearic Islands, with about 100 non-apomictic species endemic to the archipelago, is one of the most diverse of the Mediterranean basin. The origin and evolutionary relationships of this endemic flora has been debated since the phytogeographic approach of KNOCHE (1922). The identification of the closest relatives of many Balearic endemic taxa is to a high degree uncertain because most of the available knowledge is using intuitive comparisons based on morphological characters (KNOCHE 1922). Chromosomal data have served as the basis for a classification of Mediterranean endemic taxa in four categories (paleoendemism, apoendemism, patroendemism, and schizoendemism), according to their age, taxonomic isolation, and closest relationships (FAVARGER & CONTANDRIOPOULOS 1961). This cytogenetic approach helps extend our knowledge on the endemic flora of the major Mediterranean islands (CARDONA & CONTANDRIOPOULOS 1977, 1979). Despite the existence of an earlier cytogenetic review (CONTANDRIOPOULOS & CARDONA 1984), the current stage of karyological knowledge of the Balearic endemic flora is not satisfactory. Chromosome counts on Balearic endemics are usually based on a very

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limited number of observations, and some species lack basic chromosomal data. Recently, we started a study aimed at evaluating the patterns of karyological evolution in the Balearic endemic flora (CASTRO & ROSSELLÓ 2005), assessing the basic karyological features of previously studied taxa. In this work, we have assessed the mitotic chromosome numbers of 25 vascular plant taxa endemic to the Balearic archipelago. With this contribution, nearly half of the endemic flora of the Balearic archipelago have been revisited. MATERIALS AND METHODS Plant material

Living material (either whole plants or cuttings) was collected mostly from natural populations throughout the Balearic Islands. Living plants were transferred and cultivated in pots at the Botanical Garden of Valencia University. From some accessions of Anthyllis hystrix, A. vulneraria subsp. balearica, and Lysimachia minoricensis, seeds which were obtained from the germplasm collection of the Botanical Garden of Sóller (Balearic Islands) were analyzed. Seeds of Launaea cervicornis were provided by M.A. Conesa and M. Mus (University of the Balearic Islands) from individuals collected in the field. Seeds were germinated on solid agar in Petri dishes in a constant temperature of 20 °C and 12 hours of white light daily. Voucher specimens are preserved at VAL (Table 1). Chromosome preparation and karyotype analysis

Root tips were pre-treated with 0.002 M 8-hydroxyquinoline solution for 2 h at 4 °C and 2 h at room temperature, washed with distilled water, fixed in fresh Carnoy I solution (glacial acetic acid: absolute ethanol; 3:1) overnight and stored in 70% ethanol at 4 °C until use. For chromosome counts and karyotype determination, the root tips were hydrolyzed for 5–10 min in 1 M HCl at 60 °C, washed and stained in aceto-orcein for 4–6 h. Stained meristems were squashed in a drop of 45% acetic acid and permanent preparations were made by mounting in Canada balsam. Photomicrographs of well-spread metaphases were taken with an Olympus Camedia C-2000-Z digital camera and processed with Adobe Photoshop 7.0. Chromosome counts were made from 1–5 individuals per population, by direct observation and from the photomicrographs of at least five well-spread metaphases per individual. Chromosome measurements were made on digital images using the processing image software ImageTool 5.0. The idiograms of some taxa showing enough chromosomal resolution were obtained from the chromosome measurements of five well-spread metaphase plates from several plants. For each metaphase plate, the length of the short (S) and long (L) arms of chromosomes, as well as the length of satellites, were expressed in relative values (haploid chromosome set = 100%). For centromere position, the nomenclature of LEVAN et al. (1964) was followed. RESULTS AND DISCUSSION

A summary of the analyzed species and their chromosome numbers presented in this paper is shown in Table 1.

Chromosome numbers in Balearic endemics

435

Alliaceae Allium antoni-bolosii P. PALAU subsp. antoni-bolosii

Mallorca, Artà, Talaia Morella (39°46¢35² N, 3°21¢1² E), 420 m, calcareous crevices, in open and sunny places, 11.II.2004, M.A. CONESA (VAL 156738). 2n=30 (three individuals). No karyological knowledge was previously available for the Majorcan populations, but the chromosome number agrees with previous counts from single accessions from Minorca and Cabrera islands (GARBARI et al. 1991, ROSSELLÓ et al. 1993). The chromosomes showed a wide range of size variation (6–15 µm) and the karyotype was composed of five pairs of metacentric, nine submetacentric and one subtelocentric pairs. Chromosome morphology and size agree with the details given by ROSSELLÓ et al. (1993) for plants from other Balearic Islands, and no interpopulation variation was evident concerning gross karyotype morphology. No satellite was observed in the individuals studied. Allium antoni-bolosii P. PALAU subsp. eivissanum (GARBARI et MICELI) N. TORRES et ROSSELLÓ

Ibiza, Sant Antoni de Portmany, Es Port des Torrent (38°57¢43² N, 1°15¢25² E), 25 m, clearing patches with thin soil in low calcareous scrub, 17.XI.2004, N. TORRES & J.A. ROSSELLÓ (VAL 156739). 2n=30 (five individuals). Ibiza, Sant Josep de sa Talaia, Ses Salines (38°50¢47² N, 1°22¢30² E), 1 m, basic soil on shaded slopes, 18.XI.2004, N. TORRES & J.A. ROSSELLÓ (VAL 156740). 2n=30 (five individuals). The two accessions sampled showed the same chromosome number as that reported for plants collected at the type locality (MICELI & GARBARI 1987). The chromosome complement is similar in morphology and size to the typical subspecies, suggesting that no major chromosomal rearrangements have occurred within the species. Western (subsp. eivissanum; Ibiza and Formentera islands) and eastern (subsp. antoni-bolosii, Mallorca, Minorca, and Cabrera islands) populations are very closely related concerning their morphology, leaf anatomy and karyology (ROSSELLÓ et al. 1993). On the basis of the base chromosome numbers reported in the genus (x=7, 8), the Balearic populations are polyploid (MATHEW 1996). A. antoni-bolosii belongs to Allium sect. Scorodon KOCH and is closely related to the A. cupani RAFIN.-A. hirtovaginatum KUNTH complex (MICELI & GARBARI 1987, GARBARI et al. 1979). Interestingly, only chromosome numbers 2n=16 and 2n=14 have been reported for the diploid members of the complex, A. cupani and A. hirtovaginatum, respectively (GARBARI et al. 1979). Thus, the hypothesis of an allopolyploid origin of A. antoni-bolosii from x=7 and x=8 ancestors (now absent from the Balearic Islands) should not be discarded, although other explanations (autotetraploid or allopolyploid origin through x=8 ancestors and later fusion of a pair of chromosomes) are also plausible. Given that concerted evolution of ribosomal multigene families is not the dominating process in Allium (MES et al. 1999), the search for divergent ITS paralogues (or chimeric sequences) in A. antoni-bolosii could be a reliable molecular approach to assess its origin.

2n=70

Anthyllis hystrix (WILLK. ex BARCELÓ) CARDONA, CONTANDR. et SIERRA

2n=16

2n=56 2n=20 2n=55

Crocus cambessedessi J. GAY

Cymbalaria fragilis (J.J. RODR.) A. CHEVAL. Euphorbia fontqueriana GREUTER Galium crespianum J.J. RODR.

Galium friedrichii N. TORRES, L. SÁEZ, MUS et ROSSELLÓ

2n=18

Biscutella ebusitana ROSSELLÓ, N. TORRES et L. SÁEZ

2n=44 2n=66

2n=66

2n=55, 66

2n=12 2n=44 2n=12 2n=16

A. vulneraria L. subsp. gandogeri (SAGORSKI) W. BECKER* Arenaria bolosii (CANIG.) L. SÁEZ et ROSSELLÓ Aristolochia bianorii SENNEN et PAU Astragalus balearicus CHATER

Anthyllis vulneraria L. subsp. balearica (COSS. ex MARÈS et VIGIN.) O. BOLÒS et VIGO 2n=12

Ibiza, Sant Antoni de Portmany, Es Port des Torrent Ibiza, Sant Josep de sa Talaia, Ses Salines

2n=30

Mallorca, Sóller, Serra d’Alfàbia Mallorca, Sóller, Serra de Son Torrella Mallorca, Puig Major, Sa Coma de n’Arbona Mallorca, Artà, Colònia de Sant Pere Mallorca, Escorca, Puig de Massanella Mallorca, Pollença, Coll de la Creueta Mallorca, Pollensa, Mortitx, Puig de Ses Parades Cabrera Ibiza, Sant Miquel de Balansat, Es Penyal de s’Aguila Ibiza, Sant Mateu d’Albarca, Cala Albarca Mallorca, Pollença, Coll de la Creueta Mallorca, Escorca, Puig Major Minorca, Ciutadella, Cala Morell Minorca, Maó, Cap Favaritx Minorca, Ferreries, El Pilar Minorca, Ferreries, Barranc d’Algendar Mallorca, Escorca, Puig de Massanella Mallorca, Escorca, Puig Major Mallorca, Pollença, Coll de Sa Creueta Mallorca, Escorca, Puig de Massanella Mallorca, Caimari, Salt de la Bella Dona Mallorca, Pollensa, Mortitx Mallorca, Sóller, Serra d’Alfàbia Ibiza, Sant Josep de sa Talaia, Ses Roques Altes Ibiza, Sant Joan de Labritja, Els Cingles Negres

Minorca, Ferreries, Barranc d’Algendar Minorca, Mercadal, Cap de Cavalleria Minorca, Ferreries, Ets Alocs Minorca, Ciutadella de Menorca, Marina de Curniola

Mallorca, Arta, Talaia Morella

Accession

2n=30

Chrom. number

Allium antoni-bolosii P. PALAU subsp. antoni-bolosii Allium antoni-bolosii P. PALAU subsp. eivissanum (GARBARI et MICELI) N. TORRES et ROSSELLÓ

Taxon

VAL 156756 VAL 156757 VAL 156758 VAL 156840 VAL 156750 VAL 148471 VAL 156759 VAL 156760 VAL 148472 VAL 156749 VAL 148497 VAL 156763 VAL 156764 VAL 156765 VAL 156782 VAL 156778 VAL 156751 VAL 148482 VAL 148483 VAL 156774 VAL 156775 VAL 156776 VAL 156777 VAL 156728 VAL 156727

VAL 156752 VAL 156753 VAL 156754 VAL 156755

VAL 156739 VAL 156740

VAL 156738

Voucher

Table 1. A summary of the analyzed species and accessions and their chromosome numbers. An asterisk denotes that the taxon is not endemic to the Balearic Islands.

436 M. Castro & J.A. Rosselló

2n=14 2n=24 2n=20

Lotus tetraphyllus L.f.

Lysimachia minoricensis J.J. RODR. Phlomis italica L.

2n=18 + 0-2B 2n=20 2n=20

Viola jaubertiana MARÈS et VIGIN. Viola odorata L. subsp. stolonifera (J.J. RODR.) ORELL et ROMO

2n=66

Rubia balearica (WILLK.) PORTA subsp. balearica 2n=18 + 0-1B

2n=22

Primula acaulis (L.) L. subsp. balearica (WILLK.) GREUTER et BURDET

Sibthorpia africana L.

2n=40

Polygonum romanum JACQ. subsp. balearicum RAFFAELLI et L. VILLAR

2n=20 + 0-1B

Mallorca, Puig de Massanella Mallorca, Escorca, Puig Major Mallorca, Fornalutx, Balitx d’en Mig Mallorca, Caimari, Salt de la Bella Dona Mallorca, Escorca, Puig Major Mallorca, Pollença, Coll de Sa Creueta Mallorca, Fornalutx, Balitx d’En Mig Minorca, Ferreries, near Es Pas des Revull Ibiza, Sant Mateu d’Albarca, Cala Albarca Mallorca, Escorca, Puig de Massanella Mallorca, Pollensa, Mortitx, Puig de Ses Parades Minorca, Ferreries, Barranc d’Algendar

Minorca, Ciutadella, west face of Cala Morell Minorca, Ciutadella, east face of Cala Morell

Mallorca, Escorca, Gorg Blau Mallorca, Felanitx, Cala Sa Nau Mallorca, Capdepera, Es Carregador Mallorca, Artà, Cala Matzocs Mallorca, Santa Margalida, Son Bauló Mallorca, Manacor, Porto Cristo Minorca, Es Mercadal, Tirant Minorca, Es Mercadal, Binimel.là Minorca, Maó, Binidalí Mallorca, Escorca, Puig de Massanella Minorca, Ferreries, Barranc d’Algendar Minorca, Ferreries, Cala Galdana Botanical Garden of Sóller Mallorca, Calvià, S’Esclop Mallorca, Pollensa, Mortitx Mallorca, Escorca, Puig de Massanella Mallorca, Escorca, Puig Major Minorca, Ferreries, Sant Antoni de Ruma

2n=32 2n=18

Globularia majoricensis GAND. Hypericum hircinum L. subsp. cambessedesii (COSS. ex BARCELÓ) SAUVAGE Launea cervicornis (BOISS.) FONT QUER et ROTHM. 2n=32

Ibiza, Sant Antoni de Portmany, Els Alls Formentera, El Pilar, La Mola Mallorca, Escorca, salt de la Bella Dona

2n=55, 66

VAL 156772 VAL 156773 VAL 148493 VAL 150475 VAL 148497 VAL 148498 VAL 148499 VAL 150477 VAL 156779 VAL 150476 VAL 156781 VAL 156780

VAL 156723 VAL 156771

VAL 156725 VAL 156741 VAL 156742 VAL 156743 VAL 156744 VAL 156745 VAL 156746 VAL 156747 VAL 156748 VAL 156761 VAL 156800 VAL 156732 VAL 156726 VAL 156768 VAL 156769 VAL 156766 VAL 156767 VAL 156770

VAL 156729 VAL 148484 VAL 156762

Chromosome numbers in Balearic endemics

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Aristolochiaceae Aristolochia bianorii SENNEN et PAU

Mallorca, Pollença, Coll de la Creueta (39°56¢20² N, 3°16¢19² E), 50 m, maritime slopes, 15.II.2004, M.A. CONESA, M. MUS & J.A. ROSSELLÓ (VAL 148471). 2n=12 (two individuals). The chromosomes of this species are small (1–1.5 µm) and apparently similar in morphology; no further karyological details could be observed with the method used. The same chromosome count was reported by CARDONA (1976) from a single population from Mallorca. Asteraceae Launea cervicornis (BOISS.) FONT QUER et ROTHM.

Mallorca, Felanitx, Cala Sa Nau (38°40¢8² N, 1°34¢28² E), 1 m, coastal slopes, s.dat., M.A. CONESA (VAL 156741). 2n=18 (two individuals). Mallorca, Capdepera, Es Carregador (39°41¢9² N, 3°27¢17² E), 1 m, coastal slopes, s.dat., M.A. CONESA (VAL 156742). 2n=18 (one individual). Mallorca, Arta, Cala Matzocs (39°45¢29² N, 3°23¢48² E), 1 m, coastal slopes, s.dat., M.A. CONESA (VAL 156743). 2n=18 (two individuals). Mallorca, Santa Margalida, Son Bauló (39°45¢31² N, 3°9¢48² E), 5 m, calcareous cliffs near the sea, s.dat., M.A. CONESA (VAL 156744). 2n=18 (three individuals). Mallorca, Manacor, Porto Cristo (39°31¢59² N, 3°19¢32² E), 5 m, coastal slopes, s.dat., M. MUS (VAL 156745). 2n=18 (three individuals). Minorca, Es Mercadal, Tirant (40°5¢13² N, 4°6¢9² E), 1 m, coastal slopes, s.dat., M.A. CONESA (VAL 156746). 2n=18 (three individuals). Minorca, Es Mercadal, Binimel.là (40°5¢47² N, 4°2¢38² E), 1 m, coastal slopes, s.dat., M.A. CONESA (VAL 156747). 2n=18 (three individuals). Minorca, Maó, Binidalí (39°49¢29² N, 4°12¢12² E), 5 m, coastal slopes, s.dat., M.A. CONESA (VAL 156748). 2n=18 (four individuals). Chromosomes are 4–7 µm long, predominantly submetacentric and subtelocentric, with some metacentric pairs. No secondary constrictions were observed in the individuals studied. The same chromosome number was previously reported for two accessions from Minorca (DAHLGREN et al. 1971, CARDONA 1977). Brassicaceae Biscutella ebusitana ROSSELLÓ, N. TORRES et L. SÁEZ

Ibiza, Sant Miquel de Balansat, Es Penyal de s’Aguila (39°3¢44² N, 1°20¢49² E), maritime cliffs, 50 m, 26.V.2002, M.A. CONESA, M. MUS, J.A. ROSSELLÓ & N. TORRES (VAL 148472). 2n=18 (two individuals). Ibiza, Sant Mateu d’Albarca, Cala Albarca (39°3¢12² N, 1°21¢32² E), 100 m, maritime cliffs, 17.XI.2004, N. TORRES & J.A. ROSSELLÓ (VAL 156749). 2n=18 (one individual). The karyotype is composed of small chromosomes (1.5–2 µm), showing no visible centromeric constrictions. The species was already karyologically analyzed, but only a single plant was available for study (ROSSELLÓ et al. 1999). Additional plants from the type locality

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Chromosome numbers in Balearic endemics

A

B

C

D

E

F

Fig. 1. Mitotic metaphase plates of Balearic endemic species. A – Euphorbia fontqueriana (Mallorca, Puig de Massanella), 2n=20. B – Anthyllis hystrix (Minorca, Barranc d’Algendar), 2n=70. C – Anthyllis vulneraria subsp. balearica (Mallorca, Puig Major), 2n=12. D – Globularia majoricensis (Mallorca, Salt Bella Dona), 2n=32. E – Hypericum hircinum subsp. cambessedesii (Mallorca, Gorg Blau), 2n=32. F – Phlomis italica (Minorca, Sant Antoni de Ruma), 2n=20 + 1B. Arrow indicates a B chromosome. Scale bars = 10 µm.

(Es Penyal de s’Aguila) and from another population showed the same chromosome number, confirming the diploid level for Balearic populations. Caryophyllaceae Arenaria bolosii (CANIG.) L. SÁEZ et ROSSELLÓ

Mallorca, Escorca, Puig de Massanella (39°48¢13² N, 2°50¢53² E), 1250 m, sunny slopes, 8.II.2004, M.A. CONESA, M. MUS & J.A. ROSSELLÓ (VAL 156750). 2n=44 (one individual).

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A

B

C

D

E

F

Fig. 2. Mitotic metaphase plates of Balearic endemic species. A – Polygonum romanum subsp. balearicum (Minorca, Cala Morell), 2n=40. B – Galium friedrichii (Ibiza, Ses Roques Altes), 2n=44. C – Galium crespianum (Mallorca, Puig Major), 2n=55. D – Galium friedrichii (Formentera, La Mola), 2n=66. E – Cymbalaria fragilis (Minorca, Pas d’en Revull), 2n=56. F – Sibthorpia africana (Mallorca, Puig de Massanella), 2n=18. Scale bars = 10 µm.

The chromosome complement is composed mainly of small metacentric chromosomes (1–2.5 µm). CARDONA & CONTANDRIOPOULOS (1983) reported the same chromosome number for plants growing at the type locality (Puig de Massanella), but the voucher specimen could not be traced and verified. At this site, the related A. grandiflora subsp. glabrescens (WILLK.) G. LÓPEZ et NIETO FEL. also occurs, and intermediate plants of putative hybrid origin can be found. To date, only tetraploids plants of the A. grandiflora L. complex have been detected in the Balearic Islands (A. grandiflora subsp. glabrescens, 2n=44; CASTRO & ROSSELLÓ 2005).

Chromosome numbers in Balearic endemics

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Euphorbiaceae Euphorbia fontqueriana GREUTER

Mallorca, Escorca, Puig de Massanella (39°48¢13² N, 2°50¢53² E), 1250 m, slopes on sunny places, 8.II.2004, M.A. CONESA, M. MUS & J.A. ROSSELLÓ (VAL 156751). 2n=20 (one individual). Chromosomes are small in size (2–6 µm) showing mainly metacentric and submetacentric pairs (Fig. 1A); only a single pair of subtelocentric chromosomes is present. No secondary constrictions were detected in the metaphase plates. Our chromosome count agrees with the report given by CARDONA (1991) for this species. Fabaceae Anthyllis hystrix (WILLK. ex BARCELÓ) CARDONA, CONTANDR. et SIERRA

Minorca, Ferreries, Barranc d’Algendar (39°58¢19² N, 3°58¢19² E), near Es Pas des Revull, 50 m, 7.II.2004, P. FRAGA & J.A. ROSSELLÓ (VAL 156752). 2n=70 (one individual). Minorca, Mercadal, Cap de Cavalleria (40°4¢41² N, 4°5¢26² E), coastal slopes, VIII. 2004, P. FRAGA (VAL 156753). 2n=70 (five individuals). Minorca, Ferreries, Ets Alocs (40°3¢7² N, 3°59¢5² E). Plants from the living stock of the Botanical Garden of Sóller (Balearic Islands) (VAL 156754). 2n=70 (three individuals). Minorca, Ciutadella de Menorca, Marina de Curniola (40°3¢10² N, 3°53¢27² E), VIII.2004, P. FRAGA (VAL 156755). 2n=70 (five individuals). Metacentric and submetacentric chromosome pairs are predominant in the complement, but due to their small size (2–3 µm), no other karyological features could be determined (Fig. 1B). The observed 2n=70 number differs from the 2n=84 (n=42) cytotype reported by CARDONA & CONTRANDRIOPOULOS (1983) and later figured by CARDONA et al. (1986) from a single population (Sa Mola de Fornells). These authors reported a normal meiosis in the pollen grains of A. hystrix. However, they pointed out that several bivalents showed connections (CARDONA et al. 1986: Fig. 6a). A reinterpretation of this figure (using their figure 6b on A. hermanniae L. as reference for the visualization of centromeric constrictions) revealed an approximate number of n=35–36, which matches our results obtained on root tissues. Thus, the 2n=84 count for the Balearic plant should be viewed with great caution and should be verified. On the basis of the 2n=70 counts, A. hystrix is a high polyploid (decaploid, x=7), and contrasts with the diploid level (2n=14) of the closely related A. hermanniae (CARDONA et al. 1986, CUSMA et al. 2002). Anthyllis vulneraria L. subsp. balearica (COSS. ex MARE`S et VIGIN.) O. BOLO`S et VIGO

Mallorca, Sóller, Serra d’Alfabia (39°43¢53² N, 2°42¢29² E), 900 m, vertical cliffs, 2.XII.2004, M.A. CONESA, P. FRAGA & J.A. ROSSELLÓ (VAL 156756). 2n=12 (one individual). Mallorca, Sóller, Serra de Son Torrella (39°47¢8² N, 2°45¢59² E), 800 m, calcareous cliffs and slopes, 2.IX.2004, M.A. CONESA, M. MUS & J.A. ROSSELLÓ (VAL 156757). 2n=12 (two individuals).

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B

A

C

D

Fig. 3. Haploid idiograms of selected Balearic endemic species. A – Lotus tetraphyllus, 2n=14. B – Crocus cambessedesii, 2n=16. C – Phlomis italica, 2n=20. D – Lysimachia minoricensis, 2n=24. Scale bars = 5 µm.

Mallorca, Puig Major, Sa Coma de n’Arbona (39°47¢41² N, 2°46¢41² E), vertical cliffs. Seeds from the germplasm collection of the Botanical Garden of Sóller (Balearic Islands) (VAL 156758). 2n=12 (five individuals). The karyotype of this taxon is composed of small chromosomes (1.5–3.5 µm), with three metacentric, one submetacentric, and two subtelocentric pairs (Fig. 1C). This is the first chromosome count of this Majorcan endemic taxon. BENEDÍ (2000) reported 2n=12 for this subspecies on the basis of the chromosome counts given by DAHLGREN et al. (1971) (C. BENEDÍ, in litt.). These authors, however, clearly stated in their paper that the plants analyzed from NE Mallorca and Minorca (where subspecies balearica is absent) belong to A. vulneraria subsp. gandogeri (SAGORSKI) W. BECKER (sub A. vulneraria subsp. praepropera (A. KERN.) BORNM.). Chromosome counts of A. vulneraria subsp. gandogeri were determined for comparative purposes (Mallorca, Arta, Colonia de Sant Pere (39°43¢53² N, 3°16¢6² E), 1 m, rocky soils, 13.X.2004, M.A. CONESA & J.A. ROSSELLÓ VAL 156840) and also showed 2n=12. No significant karyotype differences were found between subspecies balearica and gandogeri. Astragalus balearicus CHATER

Mallorca, Pollensa, Mortitx, Puig de Ses Parades (39°53¢6² N, 2°54¢23² E), slopes, 400 m, 2.XII.2004, M.A. CONESA & J.A. ROSSELLÓ (VAL 156759). 2n=16 (two individuals).

Chromosome numbers in Balearic endemics

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Cabrera, without locality. Plants from the germplasm collection of the Botanical Garden of Sóller (Balearic Islands) (VAL 156760). 2n=16 (five individuals). The karyotype of this species is composed of small chromosomes (1.5–3 µm), with four metacentric, three submetacentric, and one subtelocentric pairs. The same chromosome number was previously reported from single accessions from Mallorca (GUINOCHET & LEFRANC 1972) and Minorca (CARDONA 1977). Lotus tetraphyllus L.f.

Mallorca, Escorca, Puig de Massanella (39°48¢13² N, 2°50¢53² E), 750 m, slopes on an evergreen oak forest, 8.II.2004, M.A. CONESA, M. MUS & J.A. ROSSELLÓ (VAL 156761). 2n=14 (one individual). Minorca, Ferreries, Barranc d’Algendar, near Es Pas des Revull (39°58¢16² N, 3°57¢36² E), shady slopes 100 m, 7.II.2004, P. FRAGA & J.A. ROSSELLÓ (VAL 156800). 2n=14 (two individuals). Minorca, Ferreries, Cala Galdana towards Cala Macarella (39°56¢39² N, 3°56¢53² E), 100 m, 7.II.2004, P. FRAGA & J.A. ROSSELLÓ (VAL 156732). 2n=14 (two individuals). The karyotype is composed of medium-sized chromosomes (3–4 µm), showing five submetacentric and two metacentric pairs (Fig. 3A). No secondary constrictions were observed. Our results agree with the counts of DAHLGREN et al. (1971) and CARDONA (1973) on two samples from Minorca. Globulariaceae Globularia majoricensis GAND.

Mallorca, Escorca, salt de la Bella Dona (39°48¢14² N, 2°53¢41² E), 450 m, calcareous cliffs in shaded places, 14.II.2004, M.A. CONESA & J.A. ROSSELLÓ (VAL 156762). 2n=32. The karyotype of this species comprises small chromosomes (2–5 µm) mostly metacentric and submetacentric, with some subtelocentric pairs (Fig. 1D). Our results agree with previous counts by CONTANDRIOPOULOS (1978) and CARDONA & CONTANDRIOPOULOS (1980) reporting the same chromosome number. The deviating aneuploid number 2n=62 given by SCHWARTZ (1963) for this species has not been confirmed again and should probably be discarded. In fact, infraspecific cytotypes, either aneuploid or polyploid races, have been rarely detected in the genus (CONTANDRIOPOULOS 1978). Available evidence suggests that this Balearic endemic is tetraploid (x=8). Plants from the Iberian peninsula and southern France that are morphologically related to G. majoricensis (e.g. G. vulgaris L., G. valentina WILLK.) show the tetraploid and (rarely) octoploid levels (VERLAQUE et al. 1995), and no diploids are known. It is therefore likely that in this complex polyploidy predated diversification. Hypericaceae Hypericum hircinum L. subsp. cambessedesii (COSS. ex BARCELÓ) SAUVAGE

Mallorca, Escorca, Gorg Blau (39°48¢46² N, 2°49¢29² E), 650 m, calcareous cliffs in a stream, 14.II.2004, M.A. CONESA & J.A. ROSSELLÓ (VAL 156725). 2n=32 (two individuals).

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The karyogram of this taxon showed small punctiform chromosomes (1.5–2 µm), without visible centromeric constrictions (Fig. 1E). Surprisingly, a previous count from the same population by REYNAUD (1986) reported 2n=40. According to this author, Hypericum sect. Androsaemum GODR., to which the Balearic taxon belongs, is characterized by x=10. This statement was credited on the basis of her original work on H. grandifolium CHOISY (2n=40), H. hircinum subsp. hircinum (2n=40), and H. ´inodorum MILL. (2n=40), as well as on previous counts (2n=40) given by ROBSON (1981) for the former two taxa. However, contradictory results on species from the section Androsaemum were recently reported by MATZK et al. (2003). These authors indicated original counts for H. androsaemum L. (2n=36), H. foliosum AITON (2n=32), H. grandifolium (2n=32), H. ´inodorum (2n=40), and H. hircinum subsp. hircinum (2n=32). Given these constant differences in chromosome number within the same taxa of the section Androsaemum made by three independent teams, it is likely premature to invoke technical errors to explain them. However, what is even more surprising is the report of two different chromosome counts (2n=32 and 2n=40) within the same population of H. hircinum subsp. cambessedesii, which is composed of less than a few dozen individuals. REYNAUD (1986) stated that the base chromosome number in the section Androsaemum was x=10. However, this hypothesis can be reinterpreted in a different way in the light of the 2n=32 counts. If the base chromosome number in the section was x=8 instead of x=10, the two different numbers within H. hircinum subsp. cambessedesii, 2n=32 and 2n=40, might be due to the presence of anomalous pentaploid cells (2n=40) in some tissues besides regular tetraploid complement (2n=32). In this respect, it is interesting to note that our chromosome counts and those from MATZK et al. (2003) were made on root tip cells, whereas REYNAUD (1986) counts were obtained from ovary cells from fixed flowers in the field. Karyological lability could be widespread in the genus since somaclonal variation in respect to chromosome number was reported in tissue culture-derived plants of H. perforatum L. plants (BRUTOVSKÁ et al. 1998). Iridaceae Crocus cambessedessi J. GAY

Mallorca, Pollença, Coll de la Creueta (39°56¢20² N, 3°16¢19² E), 100 m, maritime slopes, 18.XI.2003, M.A. CONESA, M. MUS & J.A. ROSSELLÓ (VAL 148497). 2n=16 (two individuals). Mallorca, Escorca, Puig Major (39°47¢41² N, 2°46¢41² E), 1350 m, slopes and rock crevices, on shaded exposures, 2.X.2004, M.A. CONESA, M. MUS & J.A. ROSSELLÓ (VAL 156763). 2n=16 (three individuals). Minorca, Ciutadella, west face of Cala Morell (40°3¢10² N, 3°52¢45² E), 100 m, temporary ponds, 7.II.2004, P. FRAGA & J.A. ROSSELLÓ (VAL 156764). 2n=16 (two individuals). Minorca, Maó, Cap Favaritx (39°59¢43² N, 4°15¢54² E), litoral scrub, X.2004, P. FRAGA (VAL 156765). 2n=16 (two individuals). Minorca, Ferreries, El Pilar (40°3¢7² N, 3°58¢23² E), litoral scrub, X.2004, P. FRAGA (VAL 156782). 2n=16 (two individuals). The karyotype is composed of five pairs of metacentric and three pairs of submetacentric chromosomes (Fig. 3B). Two metacentric pairs are conspicuously longer (10–12 µm) than the

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others (3–5 µm). Accessory chromosomes, reported in several species of the genus (BRIGHTON et al. 1973), were not seen. Identical chromosome counts from several Majorcan accessions of this species were recorded also by BRIGHTON et al. (1973) and NILSSON & LASSEN (1971). Lamiaceae Phlomis italica L.

Mallorca, Escorca, Puig de Massanella (39°48¢13² N, 2°50¢53² E), 1250 m, open slopes, 8.II.2004, M.A. CONESA, M. MUS & J.A. ROSSELLÓ (VAL 156766). 2n=20 + 0–1B (two individuals). Mallorca, Escorca, Puig Major (39°47¢41² N, 2°46¢41² E), 1400 m, open slopes on northern exposures, 2.X.2004, M.A. CONESA, M. MUS & J.A. ROSSELLÓ (VAL 156767). 2n=20 + 0–1B (five individuals). Mallorca, Calvia, S’Esclop (39°37¢53² N, 2°26¢26² E), s.dat., J. GULÍAS (VAL 156768). 2n=20 (five individuals). Mallorca, Pollensa, Mortitx, Puig de ses Parades (39°53¢6² N, 2°54¢23² E), shady places near calcareous cliffs, 3.X.2004, M.A. CONESA & J.A. ROSSELLÓ (VAL 156769). 2n=20 (five individuals). Minorca, Ferreries, Sant Antoni de Ruma (40°0¢56² N, 4°1¢9² E), 100 m, 6.II.2004, P. FRAGA & J.A. ROSSELLÓ (VAL 156770). 2n=20 + 0–1B (two individuals). Previously, the number 2n=20 was reported for a single accession from Minorca (CARDONA 1978). The regular chromosome complement is similar in all accessions and it is composed of ten metacentric chromosome pairs, ranging in size between 4.5–7 µm (Figs. 1F, 3C). Nevertheless, intraindividual variation concerning chromosome numbers was present in most accessions, and cells showing 20 and 21 chromosomes were usually observed (Fig. 1F). We suggest that B chromosomes are present in Balearic plants. No previous reports pointing out the presence of accessory chromosomes in the genus are known. Polygonaceae Polygonum romanum JACQ. subsp. balearicum RAFFAELLI et L. VILLAR

Minorca, Ciutadella, west face of Cala Morell (40°3¢10² N, 3°52¢45² E), 100 m, temporary ponds, 7.II.2004, P. FRAGA & J.A. ROSSELLÓ (VAL 156723). 2n=40 (three individuals). Minorca, Ciutadella, east face of Cala Morell (40°3¢10² N, 3°53¢27² E), 125 m, temporary ponds, 7.II.2004, P. FRAGA & J.A. ROSSELLÓ (VAL 156771). 2n=40 (two individuals). This is the first chromosome number count of this Majorcan endemic taxon. No karyological data concerning other subspecies of P. romanum are currently available. The karyotype is composed of small chromosomes (1–1.5 µm), similar in size, without visible centromeric constrictions (Fig. 2A). Taxa of Polygonum sect. Polygonum have the base chromosome number x=10, and on this basis it is suggested that P. romanum subsp. balearicum shows a polyploid (tetraploid) level.

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Primulaceae Lysimachia minoricensis J.J. RODR.

Seed collection from the Botanical Garden of Sóller (Mallorca). The species is extinct in the wild, and the only known population of the species was from Sa Vall (Minorca, Ferreries) (VAL 156726). 2n=24 (five individuals). Chromosomes ranged between 5–7 µm. The karyotype shows six metacentric and six submetacentric pairs (Fig. 3D). A secondary constriction is visible in the short arms of one of the submetacentric chromosome pairs. The same chromosome number was obtained by CARDONA & CONTANDRIOPOULOS (1980), but no satellite chromosomes were observed. Primula acaulis (L.) L. subsp. balearica (WILLK.) GREUTER et BURDET

Mallorca, Escorca, Puig de Massanella (39°48¢13² N, 2°50¢53² E), 1250 m, shady crevices on northern exposures, 8.II.2004, M.A. CONESA, M. MUS & J.A. ROSSELLÓ (VAL 156772). 2n=22 (two individuals). Mallorca, Escorca, Puig Major (39°47¢41² N, 2°46¢41² E), 1400 m, shady crevices on northern exposures, 2.X.2004, M.A. CONESA, M. MUS & J.A. ROSSELLÓ (VAL 156773). 2n=22 (three individuals). The chromosomes of this species are small (1–2 µm), similar in size, and without visible centromeric constrictions. Our counts agree with the observations of CARDONA & CONTANDRIOPOULOS (1980) on plants from a single accession. Rubiaceae Galium crespianum J.J. RODR.

Mallorca, Escorca, Puig Major (39°47¢41² N, 2°46¢41² E), 1400 m, shady slopes and cliffs on northern exposures, L. SÁEZ & J.A. ROSSELLÓ, 24.V.2003 (VAL 148482). 2n=55 (one individual). Mallorca, Pollença, Coll de Sa Creueta (39°56¢20² N, 3°16¢19² E), 25 m, maritime slopes, 18.XI.2003, M.A. CONESA, M. MUS & J.A. ROSSELLÓ (VAL 148483). 2n=55 (one individual). Mallorca, Escorca, Puig de Massanella (39°48¢13² N, 2°50¢53² E), 1250 m, calcareous crevices, 8.II.2004, M.A. CONESA, M. MUS & J.A. ROSSELLÓ (VAL 156774). 2n=55, 66 (one individual, mixoploidy). Mallorca, Caimari, Salt de la Bella Dona (39°48¢14² N, 2°53¢41² E), 450 m, calcareous cliffs, 5.II.2004, M.A. CONESA & J.A. ROSSELLÓ (VAL 156775). 2n=55, 66 (one individual, mixoploidy). Mallorca, Pollensa, Mortitx, Puig de ses Parades (39°53¢6² N, 2°54¢23² E), calcareous cliffs on shady places, 3.X.2004, M.A. CONESA & J.A. ROSSELLÓ (VAL 156776). 2n=66 (one individual). Mallorca, Sóller, Serra d’Alfabia (39°43¢53² N, 2°42¢29² E), 900 m, vertical cliffs, 2.XII.2004, M.A. CONESA, P. FRAGA & J.A. ROSSELLÓ (VAL 156777). 2n=66 (two individuals). See G. friedrichii for the discussion of karyological features of the species.

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Galium friedrichii N. TORRES, L. SÁEZ, MUS et ROSSELLÓ

Ibiza, Sant Josep de sa Talaia, Ses Roques Altes (38°54¢27² N, 1°14¢49² E), IV.2004, N. TORRES (VAL 156728). 2n=44 (one individual). Ibiza, Sant Joan de Labritja, Els Cingles Negres (39°4¢20² N, 1°24¢58² E), IV.2004, N. TORRES (VAL 156727). 2n=66 (one individual). Ibiza, Sant Antoni de Portmany, Els Alls (39°3¢44² N, 1°20¢49² E), IV.2004, N. TORRES, (VAL 156729). 2n=66 (one individual). Formentera, El Pilar, La Mola (38°40¢8² N, 1°34¢28² E), open slopes and maritime cliffs, 100 m, 28.VI.2003, J.A. ROSSELLÓ (VAL 148484). 2n=55, 66 (one individual, mixoploidy). In both Galium species the karyotype is composed of small chromosomes (2–3.5 µm), with mainly metacentric and submetacentric pairs. No other karyological features could be discerned with the method used. Galium crespianum and G. friedrichii are closely related species that have been confused in the past. Previously, 2n=44 was reported in both species, based on unpublished data on fixed floral buds by F. Ehrendorfer (TORRES et al. 2001). TORRES et al. (2001) cast some doubts on the accuracy of the 2n=66 record made by CARDONA (1976), since this author stated that the chromosome counts of G. crespianum were made on mitotic plates from floral buds. However, although the voucher specimen effectively did belong to G. crespianum, the plant not only lacked flowers and floral buds but it did not show any trace of inflorescence development, suggesting that this specimen was not really the fixed specimen used for cytological work. Thus, the possibility was suggested that during field work some labeling mistake with other species (e.g. Rubia balearica, 2n=66) growing in the vicinity occurred. Our work has revealed a complex cytological scenario in both Galium species, including tetraploid (2n=44), pentaploid (2n=55), and hexaploid cytotypes (2n=66), and, in addition, the somatic mosaics that combine two ploidy levels within one individual (mixoploids; Figs. 2B–D). Interestingly, this range of chromosome number variation was not detected in both species when meiotic studies were made (EHRENDORFER in TORRES et al. 2001), and this contrasts with the results reported here, made on mitotic plates from roots of potted plants collected in the field. Such variation can be explained by polyploidization and past hybridization events. The tetraploid level (2n=44) might actually be the original ploidy level for both species. The hexaploids formed via fertilization of unreduced gametes and the following hybridization between tetraploids and hexaploids could give rise to pentaploid hybrids. Then, the instability of hybrids might lead to somatic segregation in their progeny and to mixoploidy. However, sequences from the ribosomal nuclear ITS region from both species do not show single nucleotide additive polymorphisms (SNAPs) that would support a hybridization scenario (ROSSELLÓ, unpubl. data). Vegetative reproduction may be the final cause for such a cytological variation in the two Balearic species. In some plants a particular level of ploidy, or polysomaty, is specific to a certain tissue (CLOWES 1961). This has also been confirmed by works in plant tissue culture, where plantlets formed from the callus tissue can exhibit mutations and chimeras (D’AMATO 1978) or different ploidy levels (HU HAN et al. 1978). Thus, the formation of regenerating roots from the typical rootstock of G. crespianum and G. friedrichii could be involved in the genesis of chromosome variants through partial endopolyploidy and concomitant somatic segregation. Cytological comparison of transplanted plants with seedlings obtained through seed germination could be

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useful to test the view that both species share a regular complement of 2n=44 and that chromosomal instability is tissue-specific. Rubia balearica (WILLK.) PORTA subsp. balearica

Mallorca, Fornalutx, Balitx d’en Mig (39°48¢13² N, 2°43¢52² E), 325 m, cultured olive fields, on open exposures, 17.XI.2003, M.A. CONESA, M. MUS & J.A. ROSSELLÓ (VAL 148493). 2n=66 (one individual). Mallorca, Caimari, Salt de la Bella Dona (39°48¢14² N, 2°53¢41² E), 450 m, shady slopes near the road, 5.II.2004, M.A. CONESA & J.A. ROSSELLÓ (VAL 150475). 2n=66 (one individual). The chromosome complement ranges between 1.5–2 µm, showing metacentric to subtelocentric pairs. Our results agree with a previous count (CARDONA 1973), based on plants from an unspecified Majorcan population. However, the accessory chromosomes reported by CARDONA (1973) have not been observed in our samples. Scrophulariaceae Cymbalaria fragilis (J.J. RODR.) A. CHEVAL.

Minorca, Ferreries, Barranc d’Algendar (39°58¢16² N, 3°57¢36² E), 100 m, near Es Pas des Revull, vertical cliffs, 6.II.2004, P. FRAGA & J.A. ROSSELLÓ (VAL 156778). 2n=56 (three individuals). The karyotype is composed of small (1.5–3 µm), metacentric and submetacentric chromosomes (Fig. 2E). This is the first chromosome count for this Balearic endemic plant. Cymbalaria aequitriloba (VIV.) A. CHEVAL., C. hepaticifolia (POIR.) WETTST. and C. fragilis are the only species of the genus that show this high polyploid (octoploid) level (SUTTON 1988). Sibthorpia africana L.

Mallorca, Escorca, Puig Major (39°47¢41² N, 2°46¢41² E), 1400 m, shady slopes and cliffs on northern exposures, 24.V.2003, L. SÁEZ & J.A. ROSSELLÓ (VAL 148497). 2n=18 + 0–1B (one individual). Mallorca, Pollença, Coll de Sa Creueta (39°56¢20² N, 3°16¢19² E), 50 m, maritime slopes, 18.XI.2003, M.A. CONESA, M. MUS & J.A. ROSSELLÓ (VAL 148498). 2n=18 + 0–1B (two individuals). Mallorca, Fornalutx, Balitx d’En Mig (39°48¢13² N, 2°43¢52² E), 325 m, cultured olive fields, on open exposures, 17.XI.2003, M.A. CONESA, M. MUS & J.A. ROSSELLÓ, 17.XI.2003 (VAL 148499). 2n=18 + 0–1B (one individual). Mallorca, Escorca, Puig de Massanella (39°48¢13² N, 2°50¢53² E), 1250 m, calcareous crevices on shady exposures, 8.II.2004, M.A. CONESA, M. MUS & J.A. ROSSELLÓ (VAL 150476). 2n=18 + 0–2B (one individual). Minorca, Ferreries, near Es Pas des Revull (39°58¢16² N, 3°57¢36² E), shady slopes 100 m, 7.II.2004, P. FRAGA & J.A. ROSSELLÓ (VAL 150477). 2n=18 + 0–1B (two individuals). Ibiza, Sant Mateu d’Albarca, Cala Albarca (39°3¢12² N, 1°21¢32² E), 100 m, slopes near maritime cliffs, 17.XI.2004, N. TORRES & J.A. ROSSELLÓ (VAL 156779). 2n=18 + 0–1B (two individuals).

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Chromosomes of this Balearic species are uniform in size, 2.5–3.5 µm long, mostly metacentric and submetacentric. Previously, 2n=20 was reported for S. africana (LENSKI 1966, DAHLGREN et al. 1971, HEDBERG 1975, CARDONA & CONTANDRIOPOULOS 1980). However, we have observed cells showing 18 and 19 chromosomes within a single individual in all accessions (Fig. 2F); even a single individual from Massanella showed 18, 19 and 20 chromosomes. This variation is best explained by the presence of a regular complement of 2n=18 and a variable number of B chromosomes. The closely related S. europaea L. shows the same chromosome number (2n=18; HEDBERG 1975, WENTWORTH et al. 1991, MORTON 1993), as that reported here for the Balearic species. Violaceae Viola odorata L. subsp. stolonifera (J.J. RODR.) ORELL et ROMO

Minorca, Ferreries, Barranc d’Algendar, near Es Pas des Revull (39°58¢16² N, 3°57¢36² E), 100 m, shady slopes, 7.II.2004, P. FRAGA & J.A. ROSSELLÓ (VAL 156780). 2n=20 (three individuals). The karyotype of this Balearic taxon is composed of small (2–2.5 µm) metacentric and submetacentric pairs. Our count agrees with the report by CARDONA (1991) for this taxon, but the reported accessory chromosomes were not seen. Viola jaubertiana MARE`S et VIGIN.

Mallorca, Pollensa, Mortitx, Puig de Ses Parades (39°53¢6² N, 2°54¢23² E), 400 m, calcareous cliffs, 2.XII.2004, M.A. CONESA & J.A. ROSSELLÓ (VAL 156781). 2n=20 (two individuals). The chromosome sizes of this species range between 1.5–2.5 µm, and the karyotype is mainly composed of metacentric and subtelocentric pairs. No secondary constrictions were observed. Our results agree with a previous chromosome count of GUINOCHET & LEFRANC (1972), but the voucher specimen could not be traced and verified. At the Gorg Blau site, the related V. alba BESSER also grows there, and intermediate plants of putative hybrid origin have been found (V. ´balearica ROSSELLÓ, MAYOL & MUS). Acknowledgements: We thank our colleagues M.A. Conesa, P. Fraga, M. Mus and N. Torres for their generous help with field sampling. Several accessions were obtained from the living and germplasm collections of the Botanical Garden of Sóller (Mallorca) thanks to the facilities given by J.L. Gradaille and M. Vicens. Lastly, this work has been greatly improved by the comments of G. Nieto-Feliner and an anonymous referee. This work has been partly supported by funds of the project MMA 034/2002.

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CARDONA M.A. (1976): Contribución al estudio citotaxonómico de la flora de Baleares. IV. Lagascalia 6: 265–274. CARDONA M.A. (1977): Contribució a l’estudi citotaxònomic de la flora de les Balears III (A contribution to the cytotaxonomic knowledge of the Balearic flora III). Butl. Inst. Catalana Hist. Nat. 41: 83–94. CARDONA M.A. (1978): Contribució a l’estudi citotaxonomic de les Balears II (A contribution to the cytotaxonomic knowledge of the Balearic flora II). Colloq. Soc. Catalana Biol. 10–11: 51–67. CARDONA M.A. (1991): [Reports]. In: STACE C.A. (ed.), IOPB Chromosome data 3, Int. Organ. Pl. Biosyst. Newslett. 17: 7–8. CARDONA M.A. & CONTANDRIOPOULOS J. (1977): L’endemisme dans les flores insulaires méditerranéennes. Mediterranea 2: 49–77. CARDONA M.A. & CONTANDRIOPOULOS J. (1979): Endemism and evolution in the islands of the Western Mediterranean. In: BRAMWELL D. (ed.), Plants and islands, Academic Press, London, pp. 133–169. CARDONA M.A. & CONTANDRIOPOULOS J. (1980): Números cromosómicos para la flora espanola 162–182. Lagascalia 9: 272–284. CARDONA M.A., CONTANDRIOPOULOS J. (1983): [Reports]. In: LÖVE Á. (ed.), IOPB chromosome number reports LXXIX, Taxon 32: 323–324. CARDONA M.A., CONTANDRIOPOULOS J. & SIERRA E. (1986): Étude biosystématique d’Anthyllis hystrix de Minorque et d’A. hermanniae de la Méditerranée orientale et centrale. Orsis 2: 5–25. CASTRO M. & ROSSELLÓ J.A. (2005): Chromosome numbers in plant taxa endemic to the Balearic Islands. Bot. J. Linn. Soc. 148: 219–228. CLOWES F.A.L. (1961): Apical meristems. Blackwell Scientific Publications, Oxford. CONTANDRIOPOULOS J. (1978): Contribution à l’étude cytogéographique du genre Globularia L. Biol. & Écol. Médit. 5 : 3–14. CONTANDRIOPOULOS J. & CARDONA M.A. (1984): Caractère original de la flore endémique des Baléares. Bot. Helv. 94: 101–131. CUSMA T.C., FEOLI L., KOSOVEL V., BACCHETTA G. & PATUI S. (2002): Mediterranean chromosome number reports. Reports 1312–1314. Fl. Medit. 12: 475–480. DAHLGREN R., KARLSSON T.H. & LASSEN P. (1971): Studies on the flora of the Balearic Islands I. Chromosome numbers in Balearic angiosperms. Bot. Not. 124: 249–269. D’AMATO F. (1978): Chromosome number variation in cultured cells and regenerated plants. In: THORPE A. (ed.), Frontiers of plant tissue culture 1978, Proceedings of the 4th International Congress of Plant Cell and Tissue Culture, International Association for Plant Tissue Culture, Alberta, pp. 287–295. FAVARGER C. & CONTANDRIOPOULOS J. (1961): Essai sur l’endémisme. Ber. Schweiz. Bot. Ges. 71: 384–408 GARBARI F., CORSI G. & MASINI A. (1991): Anatomical investigations in the Allium cupanii-A. hirtovaginatum complex. Bot. Chron. 10: 805–808. GARBARI F., GREUTER W. & MICELI P. (1979): The Allium cupanii group: a preliminary taxonomic, caryological and anatomical study. Webbia 34: 459–480. GUINOCHET M. & LEFRANC M. (1972): [Reports]. In: LÖVE Á. (ed.), IOPB chromosome number reports XXXVII, Taxon 21: 497. HEDBERG O. (1975): A cytogenetic study of the genus Sibthorpia L. (Scrophulariaceae). Caryologia 28: 251–260. HU HAN H.T.Y., TSENG C.C., OUYANG T.W. & SHING C.K. (1978): Application of anther culture to crop plants. In: THORPE T.A. (ed.), Frontiers of plant tissue culture, International Association for Plant Tissue Culture, Calgary, pp. 123–130. KNOCHE H. (1922): Flora balearica. Étude phytogéographique sur les îles Baléares. 3. Roumégous & Déhen, Montpellier. LENSKI I. (1966): Chromosomenzahlen in der Gattung Sibthorpia (Scrophulariaceae). Naturwissenschaften 53: 710–711. LEVAN A., FREDGA K. & SANDBERG A.A. (1964): Nomenclature for centromeric position on chromosomes. Hereditas 52: 201–220. MATHEW B. (1996): A review of Allium sect. Allium. Royal Botanic Gardens Kew, Whitstable Litho Ltd, Kent. MATZK F., HAMMER K. & SCHUBERT I. (2003): Coevolution of apomixis and genome size within the genus Hypericum. Sex Pl. Reprod. 16: 51–58.

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Received 13 April 2005, first revision received 7 October 2005, second revision received and accepted 7 March 2006

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