Floating herbs without distinct stems or leaves, consisting of leaf-or grain-like fronds. Inflorescence seated in a cavity of the frond and consisting of 1-2 male flowers and a female. Flowers monoecious, without a perianth. Stamen 1. Ovary 1-celled, with 1-6 basal ovules and a funnel-shaped stigma. Seed-coat fleshy.—Genera 3, species 12.
1. Fronds rootless. Inflorescence on the back of the frond, without a spathe and consisting of 1 male and 1 female flower.—Species 6. (Including
Wolffiella Hegelm., under Lemna L.) [Subfamily WOLFFIOIDEAE.] Wolffia Horkel
Fronds with roots. Inflorescence at the margin of the frond, consisting of
2 male and a female flower enclosed by a spathe. [Subfamily LEMNOIDEAE.] 2
2. Fronds with one root each, 3-5-nerved.—Species 5. Some are used in medicine. “Duckweed.” Lemna L.
Fronds with several roots each, many-nerved.—Species 1. (Under Lemna
L.) Spirodela Schleid.
ORDER FARINOSAE
SUBORDER FLAGELLARIINEAE
[FAMILY 21.] FLAGELLARIACEAE
Climbing herbs. Leaves lanceolate, ending in a tendril. Flowers in panicles, regular, hermaphrodite. Perianth-segments 6, free, subpetaloid, yellowish or whitish, the outer somewhat shorter than the inner. Stamens 6. Anthers turned inwards. Ovary superior, 3-celled, with a solitary, inverted ovule in the inner angle of each cell. Style with 3 linear, recurved stigmas. Fruit a 1-2-seeded berry. Seeds with a mealy albumen and a small marginal embryo.
Genus 1. Species 1. Tropical and South-east Africa. Used in medicine and for plaiting-work. Flagellaria L.
SUBORDER ENANTIOBLASTAE
[FAMILY 22.] RESTIONACEAE
Grass-like herbs. Leaves linear or reduced to the sheath. Flowers in spikelets usually arranged in spikes or panicles, regular, unisexual. Perianth of 3-6 membranous or scarious segments, imbricate in bud, rarely absent in the female flowers. Stamens 2-3. Anthers 1-celled. Ovary superior, 1-3-celled, with 1-3 pendulous, straight ovules. Fruit dry. Seeds with a mealy albumen and a marginal embryo.—Genera 12. Species 230. South Africa to Nyasaland. (Plate 13.)