272 
FLORA OF THE SUNDRIBUNS. 
31. Stems more or less . elongated, with leaves and roots at 
nodes separated by distinct internodes , . , jg 
Stems very short, with a rosette of clustered leaves above 
and a tuft of roots below . . 20^ » Pistia, 
32. I eaves alternate . . . . . , • • JJ 
Leaves whorled ; small plants with articulate stems and 
almost transparent leaves , , .61. Aldrovanda. 
33. Flowers small, white . . , , 1 16* Limnanthemum. 
Flowers rather large, purplish . . , I2j. Jpomcsa, 
34. (30) Plants submerged only at high-tides . . - 35 
Plants in still water, always submerged . . *37 
35. Shrubs or herbs with leafless, fleshy, jointed stems ) flowers 
not in spathes jd 
Herbs with buried rootstock and tufted linear-lanceolate 
leaves ; flowers on a spadix enclosed in a tubular spathe 
septate within .... 20J. Cryptocoryne, 
36. blowers in sessile cone-like spikes . I4g. Arthrocnemum, 
Flowers sunk in cavities in joints of stem ' . 148. Salicornia’ 
37 * (34) Flowers at or above the surface of the water . . ^8 
Flowers as well as leaves submerged . . . *4^ 
38. Flowers white, solitary on a scape . . . *39 
blowers yellow, in racemes rising above the surface of the 
water , . . . . . ^3^* U ti^icularia. 
39. Stemless plants ; leaves all radical ^ • 40 
Stem leafy throughout . • . • . * 4^ 
40. Perianth single; fruit on a slender spiral scape, not 
winged; male spathes disarticulating . lyy, Valli%neria> 
Perianth double ; fruit on a stoutish scape, winged 178, Ottelia, 
41. (39) Leaves whorled ..... /yj, Hydrilla. 
Leaves alternate .... 178, Lagarosiphon. 
42. (37) Stamens 1-2 ; leaves linear ,,,,, 43 
Stamens numerous ; leaves cut into many filiform, 
toothed lobes 174, Ceratophyllum. 
43. Leaves entire ; stamens 2 . . , . 203. Ruppta. 
Leaves toothed ; stamen i . . . . 206, Nat as. 
44. (29) Plants growing epiphytically or parasitically on the 
stems or branches of other species . . . *45 
Plants rooted in the ground .... . 59 
45. Leafless twining parasites with long slender stems . . 46 
Leafy not twining partial parasites or epiphytes • . 47 
46. Stems and flowers green ; stamens 9 . * ^ 53* Cassytka, 
Stems yellowish, flowers w'hite ; stamens 5 . 124. Cuscuta. 
