Trmridece. 1^6 j 



2. Zi. polyrrhiza, L. Sp. PI. 970 (1753). 



Thw. Enum. 331. C. P. 2378. 



Fl. B. Ind. vi. 557. Hegelm. Lemn. tt. 13-15 {Spirodda polyrrhiza). 



Fronds \-\ in. diam., broadly obovate or orbicular, 

 7-veined, flat and bright green above, spongy and usually 

 purplish beneath, epidermal cells with sinuous walls, roots 

 many, in one tuft ; spathe 2-lipped ; stam. 2 ; ovules 1-2, 

 erect, semianatropous. 



Floating on still water, especially tanks, in the dry region ; common. 

 Fl. not seen. 



In moist temperate and many tropical regions of the world ; common 

 in England. 



2. -WOZ.FFIA, Meckel. 



Fronds subglobose, budding from the upper surface ; 



roots o ; cells of epiderm.is with straight [not sinuous] walls ; 



fl. produced from slits in the upper surface of the frond, 



sheath o; male fl. a solitary stam., anth. globose, i-celled, 



pollen smooth; fem. fl. a solitary ov,, collateral with the male, 



globose, stigma disciform, ovule solitary, orthotropous; seed 



erect, testa thick, endosperm scanty, embryo oblong. — Sp. 12 ; 



2 in Fl. B. Ind. 



W. arrhiza, Wimm. Fl. Schles. 140 (1857). 



Trim, in Journ. Linn. Soc. xxiii. 174, and Syst. Cat. Ceyl. 98. 



Fl. B. Ind. vi. 557. Hegelm. Lemn. t. ii. f. 16, 17, iii. f. 1-12. 



Frond J^ in. diam. or less, oblong-ovate, convex on both 

 surfaces, moist and spongy beneath. 



Floating on still water in the low country; apparently rare. Colombo 

 (Ferguson) ; Anuradhapura. Easily overlooked. 



Throughout the world in temperate and especially tropical regions. 

 Occurs in England. 



CXLIV.— TRIURIDEyE, 



Very slender, leafless, monoecious or dioecious annuals ; stem 

 sub-simple, wiry, flexuous, bearing a few distant small scales ; 

 fl. small or minute, in terminal racemes or corymbs, pedicels 

 bracteate ; perianth inferior, 4-8-partite, segm. subequal or 

 alternate ones longer, valvate in bud, persistent ; male fl.: — 

 stam. 3-8, fil. very short or o, anth. 2-celled, cells confluent 

 dehiscing outwards or transversely; fem. fl.: — ov. of many 

 free, i-ovuled carpels, on a central receptacle, style ventral or 

 basal, persistent, stigma punctiform, capitellate or penicillate. 



