CXLI AEACEJ?, 831 



Bhaphidopliora pertusa, Schott, in Bonplandia, Jalirg. 5 (1857) p. 45. 

 A lofty epipliytic climber; stem cylindric, reaching Ik in. in diam., 

 green, smooth, leafy. Leaves 8-18 by 6-10 in., broadly ovate, cuspi- 

 date, dark green, often with oblong holes at one side. Spathe shortly 

 pedunculate, yellow. A native of S. India, Ceylon (rare), and the 

 Malay Islands, grown in gardens. Fl. B. I. v. 6, p. 546 ; Trim. El. 

 Ceyl." V. 4, p. 361 ; Woodr. in Journ. Bomb. Nat. v. 13 (1001) p. 428. 

 Scindapsus pertusus, Schott, in JSchott & Endlich. Meletem. (1832) 

 p. 21 ; Wight, Icon. t. 781. PotJws pertusa, Roxb. Hort. Beng. (1814) 

 p. 83; Grab. Cat. p. 230. 



Order CXLII. LEMNACE^. 



Small or minute gregarious aquatic herbs, scale-like or globular, with- 

 out roots or with capillary ones, propagated by buds or bulbils, rarely 

 by seed. Fronds smooth above, spongy below. Flowers monoecious, 

 1-3, naked or enclosed in a membranous spathe. Perianth 0. Male 

 FLOWERS : Stamens 1 or 2 ; anthers 1- or 2-celled, the cells superposed, 

 dehiscing by transverse slits. Female flowers : Ovary sessile, 1-celled, 

 narrowed into a funnel-shaped style ; ovules 1-7, basal, erect or hori- 

 zontal ; stigma simple. Fruit a minute flask-shaped utricle indehiscent 

 or opening circumscissilely. Seeds erect or horizontal, 1-7 ; testa cori- 

 aceous ; albumen fleshy or ; embryo cylindric, axile. — Distrib. Species 

 about 20, cosmopolitan. 



Fronds flat, witli 1 or more roots, bearing the flowers in marginal 



clefts; an tilers 2-ceIled ; filaments slender 1. Lemna. 



Fronds minute, like grains of sand, rootless, proliferous, bearing the 



flowers on the upper surface; anthers sessile, 1-celled 2. VVolffia. 



1. LEMNA, Linn. 



Small herbs ; fronds with one or more capillary roots rising from the 

 side or the base. Flowers in marginal clefts of the frond, at first 

 enclosed in a small spathe. Male flowers in pairs, one of each pair 

 opening before the other. Stamen solitary ; filaments filiform or 

 enlarged in the middle, recurved ; anthers 2-celled, globose, the cells 

 dehiscing by transverse slits ; pollen muricate. Female flower : a 

 sohtary ovary close to the male ; ovules 1-7, anatropous, semianatropous, 

 or orthotropous. Fruit a utricle, 1-7-seeded. Seeds erect or hori- 

 zontal; embryo conic or ovoid. — Distrib. Species 17, cosmopolitan. 

 Koot solitary. 



Fronds tailed, translucent, thin, the young hastate, set crosswise 



to the parent frond ; seed horizontal 1. L. trisulca. 



Fronds not tailed, opaque, thick, the young fronds sessile ; 



seed erect 2. L. gihba. 



Eootsmany 3. L.^;polyrhiza, 



1. Lemna trisulca, Linn. Sp. PI. (1753) p. 970. Fronds sub- 

 merged, i-| in. long (not including the tail, which often attains k in. 

 long), translucent, thin, flat, elliptic-lanceolate or oblanceolate, crenate- 

 serrate near the apex, the joung fronds hastate, at length tailed and 

 attenuated into a stalk by which they remain attached to the parent 

 frond, each frond giving rise to a single root-fibre; root-cap acute. 

 Ovule solitary. Seed semianatropous, horizontal ; testa rough, grooved. 



