THE FLORA OF THE MALAY· PENINSULA

FLORA OF THE MALAY PENINSULA
VOLUME IV
ORDER CXXXV. HYDROCHARIDE1E.
Aquatic herbs; stems short stoloniferous or elongate, leafy.
Leaves linear-Ianceolate or broadly ovate. Flowers regular usually
unisexual enclosed in a spathe. Sepals free 3; petals white or
yellow. Stamens 3 to 1Z; filaments short. Ovary inferior, 1celled;
placentas parietal 3 to 6; ovules numerous; style divided.
Fruit usually baccate, rarely dehiscing. Seeds numerous. Species
about 50, whole world. (Ridl., Materials for a Flora of the Malay
Peninsula, vol. L)
Fresh-water species.
Stems elongate leafy; leaves whorled I. HYDRILLA
Stems elongate leafy; leaves alternate 2. ENHYDRIAS
Stem short; leaves radical.
Leaves linear; flowers very small; petals linear . 3. BL YXA
Leaves large ovate petioled; flowers large; petals
ovate . . 4. OTTELIA
Marine. rhizome creeping.
Leaves long linear; male flowers very numerous in a
large spathe • • . 5 ENllALUS
Leaves small ovate; males solitary 6. HALOPHILA
1. HYDRILLA, L.C. Rich.
Submerged elongate leafy plant. Leaves short in whorls of 3
or 4 or below opposite. Flowers in axillary spathes, solitary.
Males short-pedicelled; sepals ovate; petals narrower; stamens 3;
anthers ovate. Female sessile, spathe tubular. Ovary except
long. beak enclosed in spathe; styles 3 (rarely z) linear. Fruit
narrow. Seeds oblong. One or two species; all Old World tropics.
(I) H. verticillata Presl. Bot. Bemerk. IIZ; Ridl., Mat. i. 3.
Serpicula verticillata Roxb. Carom. Pl. t. 164.
Stem 6 to 1Z in. long, slender. Leaves 'z5 in. long, oblong
acute, toothed. Bab. Rare. Kelantan in the river at Kamposa.
2. ENHYDRIAS, Ridl.
Stems long, leafy. Leaves alternate, narrow linear. Flowers
solitary, in tubular spafhes, bisexual. Perianth-tube long, slender.
Fl.M.P .• .J B