Order HYDROCHARITALES 
By JoHN KUNKEL SMALL 
Aquatic or marsh-inhabiting caulescent or acaulescent herbs with root- 
stocks, the scapes, stems, and leaves usually succulent or spongy. Leaves alter- 
nate, often all basal; blades narrow and short or greatly elongate and usually 
sessile, or very wide and petioled. Flowers monoecious or dioecious or rarely 
perfect, arising from spathes, usually solitary, the pedicels sometimes greatly 
elongate. Perianth double or rarely single. Calyx of 3 herbaceous or petaloid 
sepals. Corolla of 3 thin petals, or wanting. Androecitum of 3-12 stamens 
with distinct or united filaments. Gynoecium of 3-15 united carpels; ovary 1- 
celled and with several parietal placentae or 2-15-celled. Fruit a short or 
elongate berry or utricle. 
Gynoecium 3-carpellary, or rarely 2-, 4- or 5-carpellary ; ovary 1- celled, with 3, or rarely with 2, 4 
or 5 parietal placentae; stigmas usually =p Fam. 1. ELODEACEAE, 
Gynoecium 6-9-carpellaty ; ovary 6-9-celled (imperfectly so in 
Hydromystia) ; stigmas 6-9. Fam. 2. HYDROCHARITACEAE, 
VoLUME 17, Part 1, 1909] 65 
