366 LcninaceCP. [Lemna. 



CXLIIL— LEMNACE^. 



Very small or minute monoecious, green, floating, gre- 

 garious, scale-like, fresh-water fronds, propagated by budding, 

 or by hybernating bulbs, rarely by seed ; roots o, or of 

 one or more capillary fibres produced from a point on the 

 under-surface of the frond, each terminated by an elongate 

 conical root-cap ; fl. 1-3 on each plant (rarely produced in 

 some species), most minute, naked or in a sheath, perianth o ; 

 stam. I or 2, anth. i -celled or didymous and 2-ceIled ; ov. i- 

 celled, style short, stigma truncate or funnel-shaped, ovules 

 1-7, basal in the cell; fr. a bottle-shaped membranous utricle ; 

 seeds i or more, testa coriaceous, ribbed, endosperm o, or 

 fleshy, embryo axile, cylindric, plumule in a lateral slit. 



Fronds with roots . . . . . . . .1. Lemna. 



Fronds without roots 2. WoLbFlA. 



I. ZiEMNA, Linn. 

 Fronds with one or more capillary roots, budding from 

 lateral slits of the frond ; fl. produced in separate slits from 

 the buds, at first enclosed in a short sheath ; male fl. binatc, 

 stam. I, anth. didymous, dehiscing transversely, pollen globose ; 

 fcm. fl. a solitary ov. collateral with the male, style very short 

 or o, stigma disciform, ovules i or more. — Sp. 17; 6 in Fl. 

 B. Ind. 



There are two species oi Lemna with sohtary roots in Herb. Peraden. 

 which I have failed to identify from dried specimens. One is marked 

 from 'St. Sebastian Quay, Colombo, Jany. 1885 (W. F.);' the other, a 

 much lar.i^^er plant, is ticketed, 'Z. niinflf, from Tissor Mewa, Kelvin 

 Grove, Feb. 1883 (W. P".).' These should be sought for and carefully 

 described and drawn from living specimens. 



Root solitary i. L. paucicostata. 



Roots many 2. L. polvrkhiza. 



I. Zi. paucicostata, Hcgehn. I^emnac. 139 (1868). I>iya- 

 panshi, ^V. (Moon;. 



/.. i/u'nor, .Moon, Cat. 61 ; Thw. Enum. 331 (non L.). C. P. 2379. 



II. H. Ind. vi. 556. Hegelm. Lemn. t. 8. Grift". Ic. PI. Asiat. t. 262, 

 263 (Z. minor). 



Frond l-\ in. long, as\'mmetrical, obovate or obovate- 

 oblong, nearly flat on both surfaces, obscurely 3-veined ; root 

 solitary, emerging from a small winged sheath, root-caj) acute; 

 ov. i-ovulcd, ovule erect, orthotropous. 



On still water; common. 



Throughout the Tropics, where it takes the place of the L. minor of 

 temperate regions. 



