The South African Species of Lagarosiphon

139

The South African Species of Lagarosiphon by

A. A. Obermeyer A n exam ination o f the so u th ern A frican species o f this genus revealed th a t each had a typical leaf-structure, a useful character since plants are often sterile. Very little was know n o f the life-history o f this genus until W ager's w ork appeared in 1928.* A fterw ards D r. M. E rnst-Schw arzenbach also studied the flower-biology o f L. m uscoides.f W ager observed 2 species com m on on the Highveld, L. muscoides and L. major. As the o th er three South A frican species appear closely related, it is likely th a t in general their behaviour will be sim ilar. Exam ining dried m aterial, especially o f such small dim ensions, is not very satis­ factory. Living plants m ust be studied in the m an n er in which it was done by W ager, to give us a m ore com plete picture o f th e ir life-history. As so little was know n about these species when W right m ade his com pilation for the Flora of Tropical Africa, his treatm ent o f them is unsatisfactory. Some are no better than generic descriptions and w ithout having seen the types, it is im possible to recognize the plants concerned. Lagarosiphon Harv. in H o o k ., Jo u rn . Bot. L ond. 4: 230 (1841). f., Gen. PI. iii: 450 (1883). Phill., G en. ed. 2: 58 (1951).

Benth. & H ook,

Subm erged, dioecious, rooted herbs from a perennial rhizome w ith long terete leafy ste m s; branches arising from inside a spathe next to a flower. Leaves widely spaced below, dense above, alternate, subopposite o r w horled; with 2 m inute narrow ly ovoid intravaginal squam ulae; m argin to o th ed (each to o th unicellular); lam ina with variation in cell structure. Male inflorescence axillary; spathes 2 united bracts, obovate o r ovate to lanceolate, com pressed o r cup-shaped, d en tate; the axis (rudim entary inflore­ scence) producing num erous pedicellate flowers (up to 50 were counted in L. m ajor) consecutively; the buds (in S outh A frican species) become detached and rise to the surface before anthesis where they expand ; p erianth in 2 whorls o f 3 segm ents each (the o u ter segm ents slightly n arrow er), recurving suddenly to form a bell-shaped structure that floats on the w ater; stam ens 3, the filam ents when expanded situated parallel to the w ater-surface with the anthers at right angles to them ; each pollen-sac containing 4 tetrad s, grains large; stam inodes 3, longer th an the stamens, papillate and usually coloured above, joined at the to p , acting as a sail. Female inflorescence axillary; spathes 2, fused, narrow ly oblong, ovoid o r cylindrical, entire o r toothed, containing 1-2-3 flowers (when the capsule develops the inner spathe, which is usually larger, splits centrally along the m id rib ); perianth-tube exserted laterally near the apex of the spathes, lengthening and giving off gas-bubbles continuously inside the delicate tube to buoy it up so th a t it will reach the surface (u ltim ate length o f flower depends on the species: in L. muscoides up to 25 cm, in L. major 15 cm : if it has not reached the surface by then, it will die); limb 6-lobed; stam inodes 3, small, filiform ; ovary 1-locular w ith 3 parietal placentas; styles 3, adnate to the perianth-tube, each divided above into 2 long, papillate, often brightly coloured stigm as; ovules 6-30, o rth o tro p o u s, funicle sh o rt o r long, straight o r bent. Capsule ovoid o r cylindrical, attenuate at the apex into a beak (the persistent base c f the perianth), protruding from to rn spathevalves; becom ing m ucilaginous and bursting irregularly and so dispersing the seeds; * Wager, V. A. in Trans. Roy. Soc. S.A. 16: 191-204 (1928). + Ernst-Schwarzenbach, M. in Ber. Schweiz. Bot. Ges. 5: 56-58 (1945).

140 seeds cylindrical, with a short stipe at the base, pointed at the apex, size varying with each species, closely ribbed o r honeycom bed, buoyant at first, sinking later (viable only after ab o u t 6 m onths in L . muscoides and L. m ajor, unknow n in other species). A b o u t 16 species found in A frica, 2 endem ic to M adagascar. L. major is reported as an adventive in E urope and New Zealand. Leaves thin, transparent, 0 -5 -2 mm broad, cells usually longer than broad: Leaves with a hyaline margin consisting o f at least 3 layers o f cells without chlorophyll l . L. muscoides Leaves green to the margin, teeth on small excrescences: Leaves in verticils o f 6 -8 ; central band usually narrow and the cells not much different from rest o f lam ina................................................................................................. 2. L. verticillifolius Leaves alternate or sometimes in verticils o f 2 -5 ; central band usually wide, at least near the base, with the cells much larger and with transverse sep ta............................. 3. L. crispus Leaves more solid, opaque, 2-3 mm broad, cells small, som ewhat papillose-rhomboid: Teeth o f leaves minute, blunt, ascending.................................................................................... 4. L. major Teeth o f leaves on triangular excrescences, sharp, patent.................................................... 5. L. ilicifolius

1. L. muscoides Harv. in H ook. Journ. Bot. Lond. 4: 230, t. 22 (1841). W rieht in F T.A . 7: 3 (1897); F.C. 5, 3: 1 (1912). M arloth, Flora o f S.A. 4: 15, fig. 6 t. 2 (1915). W ager in Trans. Roy. Soc. S.A. 16: 191 (1928). Ernst-Schw arzenbach in Ber. Schweiz. Bot. Ges. 55: 56 (1945). Syntypes: C ape, Albany, Zeyher mbo: M kuzi G am s Reserve, Tinley 443.

2549 -f>; 2551 2 (PR E ,

Easily distinguished by the m any-leaved w horls. 3. L. crispus RendJe in J. Linn. Soc. Bot. 30: 381, pi. 31, fig. 8-17(1895); F.T.A . 7: 4 (1897). Type: T anganyika, betw een Uyui and coast, Taylor (BM. holo.). L. tsotsorogensis Brem. & O berm . in A nn. Tvl. M us. 16: 401 (1935). Type: Bechuana­ land, Tsotsoroga Pan, van Son T R V 28853 (P R E . holo.). Stems filiform, 1-2 mm in diam . Leaves alternate, sub-opposite to verticillate above, usually densely spaced on the stem s, spreading, soft, thin, transparent, linear, average size 14 by 0 -5 mm, m arginal cells chlorophyllous, the many, sharp curved teeth pointing upw ards, situated on sm all, trian g u lar excrescences; leaf-tips bi-dentate; central area narrow to very b ro ad , consisting o f larger lacunar cells w ithout o r with very little chlorophyll, usually w ith transverse septa, m idrib distinct. Mate inflorescence: spathe-valves cup-shaped, obovoid. a b o u t 2 m m long, acute at first becom ing broad and gaping during anthesis, w ith a b o u t 8 teeth on each side. Female inflorescence: spathes form ing a narrow ovoid tube 2 -5 m m long, entire or with a few small teeth, apex entire at first, becom ing b ilobed; p erian th w hite, limb about 2 m m in d iam .; ovary with 24-30 ovules, funicles a b o u t as long as the ovules; stigmas w ith short papillae. Capsule ovoid, acum inate, a b o u t 3 mm long, m any-seeded; seeds 1 mm long, turbinate, with raised ridges w hich have transverse septa (in the dried state). Recorded from East A frica, S outhern Africa, eastern and northern T ransvaal. K e n y a . — N orth ern

Rhodesia, B echuanaland. South W est

Province, Sololo, G illen 13683.

T a n g a n y i k a . — K ivingo,

Greenway 1979.

S o u t h e r n R h o d e s ia .— U rungw e, Zam besi Valley, M enswa Pan, Wild 4069; 17 miles E.S.E. o f C hirundu Bridge, D rum m ond 5404 (S R G H ). Lower Sabie, W ild 2318 (SR G H ). Subungwe, M araw a ro ad , Davies D1968 (SR G H ). T r a n s v a a l . — Soutpansberg:

348; Verdoorn 2273. 4198.

L im popo River, farm W eipe, in pan, Codd & de W inter Pilgrim ’s R est: Leeupan near Tshokw ane, van der S c h iiff 2766;

B e c h u a n a l a n d .—T sotsoroga

Pan a b o u t 150 miles N. o f M aun, F.rens 351.

S o u t h W e st A f r i c a . —Caprivi S trip : K ab u ta Village in C hobe River, M unro. O k a­ vango: N iangana, O kavango River, D inter 7246. G rootfontein: West o f A n dara, M erxm iiller 2096.

C haracteristic o f I . crispus Rendle are its small flowers (limb 1 -5-2 mm in diam .), small, broadly ovoid capsules a b o u t 2-5 mm long and m any seeds which are 1 m m long

144 (ovary w ith 24-30 ovules). In the S outh A frican specim ens the leaves show the ch arac­ teristic lacu n ar b road central band w ith transverse septa at least in lower half. However, som e specim ens from tropical A frica have the leaves longer (2 cm instead o f 1) and the b an d indistinct. W hether they belong to an o th e r species could n o t be decided here. In van der Schijff 4198, three setaceous appendages were noticed at the base o f the ovary sim ilar to those seen in Schoenfelder 5648 (L . muscoides H arv.) from South W est Africa. They m ay be the rudim ents o f ab o rted flowers. Rendle noted th a t he found no intrafoliar stipules. They were present in som e specimens, but others appeared to be w ithout them ; they m ay be early deciduous; such delicate organs easily disinte­ grate durin g pressing and drying. Som etim es the plants are m uch branched, foliose, w ith the leaves rath er long (2 cm). This could be its habit when, th ro u g h external circum stances, n atu ral sexual rep ro d u ctio n is ham pered. The species is ap p aren tly related to L. tenuis Rendle.

F ig . 2 .— Lagarosiphon crispus Rendle. Part o f leaf seen from above showing midrib (m) and network o f veinlets (v); ci, large central cells; co smaller outer cells (Frens 351V

145 4. L. m ajor (Ridley) M oss apud Wager in T rans. Roy. Soc. S.A. 16: 193 (1928). M ason in New Zeal. Journ. Sci. 30: 384 (1960). W ild in K irkia 2: 39, t. 13, d (1961). L. muscoides H arv. var. major R idley in J. Linn. Soc. Bot. 22: 233 (1886).* Syntypes: Cape, V ictoria East, U m dizine River, Cooper 17 (K , P R E ); Transvaal, B ro n k h o rstspruit, Rehmann 6559 (K ); Bethal, T rigardtsfontein, Rehmann 6678 (K). E/odea crispa hort. non Lagarosiphon crispus Rendle. Stems a b o u t 3 mm in diam ., usually firm. Leaves alternate, laxly spaced below, dense above form ing obtuse, b ro ad apices, spreading-recurved, soft, usually fairly firm, opaque, linear, average size 16 by 2 m m (occasionally up to 3 cm ); apex obtuse to acute to accum inate, m argin w ith the o u term o st row o f cells hyaline, producing minute, blunt, closely-spaced te e th ; leaf-tips w ith teeth sim ilar to m arginal; m idrib sunk above, prom inent below ; lam ina w ith sm all papillose, rhom boid cells when viewed from above, those o f the m idrib slightly longer and larger. M ale inflorescence: spathe-valves oblong-lanceolate, 5 by 3 m m , w ith a b o u t 8-9 teeth on each side, bearing about 50 flowers consecutively, p erian th pinkish. Female inflorescence', spathe-valves ovoid, up to 5-5 by 2-5 mm, w ith a b o u t 12 teeth on one side and ab o u t 6 on the o th er; perianth pink, m axim um length 15 cm ; ovary flask-shaped, stigmas red. ovules a b o u t 12. Capsule ovoid, a b o u t 5 mm lo n g ; seeds a b o u t 2 mm long. W idespread in southern A frica from the eastern Cape. O range Free State, T ransvaal to Southern Rhodesia. R ecorded as an adventive from E urope and N ew Zealand. C a p e . — King N

W illiam ’s T ow n: near K ing W illiam ’s Town, Sim 1561.

a t a l .— N ew castle:

W. o f L aingsnek-Q uaggasnek Rd., Edwards 2369.

O r a n g e F ree S t a t e .— Bosh ofT :

S m its k r a a l,

B urtt Davy in PRE 10731.

T r a n s v a a l . — Piet

R etief: Kleber S tan d erto n : Schlechter 3464. Belfast: Wager N H 49186 $ ; Franks in PR E 9770. P reto ria: Rietvlei D am , Repton 2001. G erm iston: Birchleigh, Wager N H 49187 $. P otchefstroom : Frederikstad. Louw 1709. R h o d e s ia . — U m tali, Tsungwesi River, Wild 4649. Salisbury, H unyani Poort D am , W ild 4146. M ato b o : M ato p o s D am , Rattray $ in SR G H 82664.

Southern

U sually sterile. Often an obnoxious w ater pest, choking pans in the Republic and Southern R hodesia. 5, L . ilicifolius Oberm., sp. nov. P lanta robusta. Caulis ca 3 m m diam . albidus. Folia alterna interdum subopposita lam ine opaca reflexa lanceolata 8 x 2 - 5 mm m argine dentibus patentibus llici simili basi triangulari. Cellulae q u adrangulare sparse papillosae. Spatharum valvae anguste ovatae d en tatae; o varium ovoideum atten u atu m 9-ovulatis. Capsula ovoidea. Semen 2 mm longum . T ype: B echuanaland, Bridge a t T oteng on the N .E. tip o f Lake N eam i, S tory 4727 (PR E , holotype). Stems a b o u t 3 mm in diam . (thinner in fertile plants), usually firm, whitish. Leaves alternate, occasionally subopposite, regularly spaced below with the internodes a b o u t 3-6 m m long, densely leafy above form ing b ro ad obtuse apices to the shoots, reflexed or recurved, fairly firm, opaque, lanceolate, average size 8 by 2-5 mm (sm aller in fertile plants) apex acute, m argin w ith the ou ter row o f cells hyaline, w ith the patent strong teeth situated on broad trian g u lar excrescences, closely spaced, leaf-tip with 2 teeth sim ilar to m arginal ones; all cells o f the lam ina small, similar, squared and som ew hat papillose viewed from above, m idrib faint depressed, prom inent-below , purplish in dried specimens, its cells som ew hat longer and narrow er. M ale inflorescence unknow n. Female inflorescence: spathe-valves narrow -ovate, 4 mm long, toothed or * F. C. 5, 3: 1 (1912).

146 entire, acute, pale wine red; perian th pale lilac (Story); ovary ovoid, attenuate, ovules a b o u t 9, funicle erect, short. Capsule ovoid, tapered tow ards the apex, 5-7 mm long; seeds 2 mm. R ecorded from N orth ern South W est A frica (O kavango River), n o rth ern Bechu­ an alan d (Lake Ngami), Southern and N o rth ern R hodesia (Zam besi River). W est A f r ic a .—-O kavango N ative T erritory, lagoon in O kavango River at K ap ak o C am p, 4 miles W . o f M upini M ission, de Winter & M arais 4516; R untu, bog an d riverbed o f O kavango River, M erxm iiller 1890; N iangana, O kavango River, Dinter 7202a. South

B e c h u a n a l a n d . — Bridge at T oteng on the N .E. tip o f Lake Ngam i, Story 4727 (P R E , holo.); M cConnell in S R G H 6 8 9 0 l; M aun, T ham alakane River, M cConnell in S R G H 68903. S o u t h e r n R h o d e s ia .— Zam besi

in T R V 9066;

River ju st above V ictoria Falls, Galpin 1021; Young 1592; Sim 19176; W ild 3111 (SR G H ).

Wilde

N o r t h e r n R h o d e s ia .— Livingstone, Zam besi River, Greemvay 6252. M angu, Luanginga River, ab o u t 4 miles N .W . o f Sandaula P ontoon, Drummond & Cookson 6586.

U sually sterile in which case it is m uch coarser than the female plants collected at lake N gam i. N o t e .— The tropical A frican types o f L. schweinfurthii Casp., L. steudneri C asp., L. cordofanus Casp. and L. fischsri G iirke were n ot found at Berlin: probably destroyed in 1943'. A

cknow ledgm ents

F o r loan o f m aterial I sincerely th an k the Keepers o f the Southern R hodesian H erbarium , Salisbury, the Bolus H erbarium , C ape Tow n, the N atal H erbarium , D urban and th a t o f the Eastern Province at the A lbany M useum . From Dr. M. E rnstSchw arzenbach we gratefully received reprints o f her w ork on this genus. Last but not least my sincere thanks to M r. J. E. D andy, K eeper o f Botany, British M useum (N atu ral H istory) for his helpful com m ents.