G68 cxxiii. iirDRocn.vRiTACE.i:. 



or 2-leaved spathe ; females solitary ; perianth superior. Sepals 3, 

 green or petaloid. Petals membranous or 0. Male floweus : Stamens 

 3-1:^ in 1-4 series ; antliers 2-celled. Female flowees : Ovary ini'ericr, 

 1-eelled ; placentas 3-G, parietal or intruded, sometimes almost meeting 

 at the axis ; ovules numerous on each placenta, auatropous or ortho- 

 tropous ; styles or style-arms 3-12. I'ruit globose or ovoid, dry or 

 pulpy (rarely dehiscent). Seeds few or many ; albumen ; embryo 

 smooth or lineate. — DisxiiiB. Warm regions of the world; genera 14; 

 species about 40. 



Stems branching, leafy ; leaves small ; spathes small, sessile. 



Leaves whorled ; styles undivided ; ovulf-s anatropous 1. IIydrilla. 



Leaves scattered ; styles notched ; ovules orthotropous ... 2. LAtiAiiosU'iiox. 

 Stems 0, or with stolons only, or a creeping roolstock. 



Leaves all long and narrow, sessile ; male scapes many- 

 llowered. 



Perianth single 3. Vali.is.xeri.i. 



Perianth double 4. Bi.yxa. 



Leaves mostly or ail petiolate ; ilowers solitary 5. Ottelia. 



1. HYDRILLA, Eid.. 



A submerged leafy fresh-water herb. Leaves short, 3-4-nately 

 whorled or the lower opposite. Flowers minute, dioecious, the males 

 shortly pedicellate, solitary in a subglobose muricate spathe, the females 

 sessile, 1-2 in a tubular 2-toothed spathe. Male floavers : Sepals 3, 

 ovate or obovate, green. Petals 3, oblong or cuneiform. Stamens 3 ; 

 anthers large, renit'orm, opening elastically. Pistillode minute. Female 

 FLOWERS : Sepals 3, linear, green. Petals 3, narrow. Ovary produced 

 beyond the spathe into a tililorin beak, 1-celled ; ovules anatropous ; 

 styles 2-3, linear, undivided ; stigmas fimbriate. Fruit subulate, smooth 

 or muricate. Seeds 2-3, oblong, minute; testa produced at both ends. 

 — DiSTRiB. Central Europe, Mauritius, Madagascar, Tropical Asia and 

 Australia ; species 1. 



1. Hydrilla verticillata, Presl, Bot. Bemerh. (1844) p. 112. 

 Fresh-\\ ater plants forming large masses ; stem slender, 1 ft. and more 

 long, with fibrous roots, much branched, flaccid, \\ith l(.)ng or short 

 internodes, often rooting from the nodes ; branches with a short 

 sheathing leaf at the base. Leaves -J— | by yv-7 in., sessile, 4—8 in a 

 whorl (the lowest often opposite), linear or linear-oblong, apiculate, 

 entire or serrulate ; midrib strong. Flowers i-i in. long ; perianth- 

 segments very variable. Fruit smooth or muricate. The little mem- 

 branous spathe of the male flowers ultimately splits and liberates the 

 flower, which rises to the top of the water, where it floats, expands, and 

 scatters its pollen. Fl. B. I. v. 5, p. 059 ; Dalz. & Gibs. p. 277 ; 

 AVoodr. in Journ. Bomb. Nat. v. 12 (1899) p. 517; Prain, Beng. PI. 

 p. 995 ; Watt, Diet. Econ. Prod. v. 4, p. 310. Hydrilla ovaUfoUa, 

 Eich. in Mem. Inst. Fr. v. 12, part 2 (1811) p. 70, t. 2 ; Trim. Fl. Ceyl. 

 V. 4, p. 123. iSerjnci'la veitlcillata, Linn. f. Siippl. (1781) p. 41(3; 

 Koxb. Cor. PI. V. 2 (179S) p. 33, t. lG-1 ; Fl. Jnd. v. 3, p. 578.— 

 Flowers : Dec. 



Common in tanks tnroughont the Presidencj'. Ivonkan : Uran (Bombay Ilarboni), 

 AVor/.s- ! Ueccan : Tanks near Poona, Co(ikc\, Woodrow; Eijapur, t'ookcl Sinu : 

 Mauchar l.nke, Utockit, llij? !— Disritin. Of the genus. 



