9- NAIADACEAE — 10. APONOGETONACEAE — II. SCHEUCHZERIACEAE 75 



FAMILY 9. NAIADACEAE 



Herbs growing in fresh or brackish water. Leaves Unear, toothed or spiny. 

 Flowers axillary, solitary or in glomerules, unisexual. Perianth Uttle developed, 

 in the male flowers simple or double, sack-like, in the female simple and sack- 

 like or wanting. Stamen i. Anthers i- or 4-celled. Pollen-grains globular 

 or ovoid. Ovary i-celled. Ovule i, erect, inverted. Style i ; stigmas 2 — 3. 

 Seed with a hard coat, exalbuminous. Embryo straight, with a large radicle 

 and a well developed plumule. 



Genus i, species 10. (Including Caiilinia A. Braun) .... Naias L. 



FAMILY 10. APONOGETONACEAE 



Aquatic herbs with a tuberous root-stock. Leaves radical, narrow, with 

 several longitudinal and many transverse nerves. Flowers in i — 4 spikes 

 connected at the base, enclosed when young in a sheath, and rising above the 

 water. Perianth of i — 3 more or less brightly coloured segments. Stamens 

 6 or more, hypogjmous, free. Anthers attached by the base, opening with two 

 longitudinal slits. Carpels 3 — 8, distinct. Ovules in each carpel 2 — 8, basal 

 or sutural, ascending, inverted. Fruits membranous, dehiscent. Seeds 2 or 

 more, erect, exalbuminous, with a straight embryo. (Under N AI ADA. 

 CEAE.) (Plates.) 



Genus i, species 20. Tropical and South Africa. Some are used as orna- 

 mental plants, especially the lattice-leaf (.4. fenestralis Hook, fil.) with 

 perforated leaves. The tubers are edible and contain starch. (Including 

 Ouvirandra Thenars) Aponogeton Thunb. 



FAMILY 11. SCHEUCHZERIACEAE 



Marsh herbs. Leaves linear, with axillary scales. Flowers in terminal 

 racemes or spikes, regular, hermaphrodite. Perianth of 6 segments, usually 

 green. Stamens 3 — 6. Anthers turned outwards ; pollen-grains ovoid. 

 Ovary 3 — 6-celled. Ovule i in each cell, ascending, inverted. Stigmas sessile. 

 Seeds exalbuminous, with a straight embryo. {JUNCAGINEAE, under 

 NAIADACEAE.) 



Genus i, species 4. North, South, and West Africa. The leaves and fruits 

 of some species are edible. [Jimcago Tourn.) . . . Triglochin L. 



SUBORDER ALISMATINEAE 



FAMILY 12. ALISMATACEAE 



Aquatic or marsh herbs, with milky juice. Leaves with axillary scales. 

 Flowers regular. Perianth of 3 sepals and 3 petals, rarely in the female flo\\ers 

 of 3 sepals only. Stamens 6 or more, rarely 3. Anthers opening outwards. 

 Pollen-grains globular. Carpels 6 or more, rarely 3, distinct or united at the 

 base. Ovules solitary in each carpel, rarely two or more, inverted. Seeds 

 without albumen ; embryo curved. — Genera g, species 15. Tropical and 

 North Africa. (Plate 6.) 



