Twenty-first, twenty-second class. 
45 
— Ovary not pedicelled (comp. Typha) . . . 20 
26. FIs united on a fleshy spadix surrounded by a sheath. 
Rad. Is cordate, hastate or sagittate . . . 27 
— Sheath 0, or (in Typha) very deciduous . . 28 
27. Spathe (or sheath) in the form of a horn. Spadix bear¬ 
ing the fem. fls at the base and above these the male 
fls, prolonged above in the form of a club Arum. 538. 
— Spathe flat, white inside. Spadix with fls up to the top; 
the upper fls male, the others hermaphrodite Calia. 539. 
28. Fls, at least the males, in globular heads, or cylindric 
spikes.. 20 
— Fls neither in heads nor spikes .... 31 
29. Ls broad, lobed. Pis growing on dry ground 
Xaothium. 359. 
— Ls linear, entire. Pis growing on marshy places 30 
30. Fls in cylindric spikes .... Typha. 536. 
— Fls in globular heads . . . Sparganium. 537. 
31 (28). Stem climbing, with spiral tendrils. Ls cordate, 
5-lobed. Bryonia. 197. 
— Stem not climbing, without tendrils . . . 32 
32. FI.-envelope composed of cal. and cor. Ls all radical 33 
— FI.-envelope simple, a perianth, or 0. Ls partly cauline 
31 
33. Stas numerous. Ls sagittate . . . Sagittaria. 528. 
— Stas 4. Ls linear-subulate . . . Littorella. 483. 
34. Ls.opp. with stinging hairs, secreting a caustic liquid 
Urtica. 505. 
— Ls (except perhaps the first) altern., without stinging 
hairs. 35 
35. Fem. fls without perianth, but with 2 bracts which are 
enlarged at maturity and enclose the fr. Atriplex. 489. 
— Male and fem. fls with a perianth (ls oval or oval- 
rhomboidal). Amaranthus. 4§4. 
Cl. 22. Dioecia. 
1. Ligneous pis (trees and shrubs) . . . . * 2 
— Herbaceous pis (and climbers) .... 15 
— Grass-like pis. Carex. 609. 
2. Small dichotomous shrubs, with opp. ls, tree-parasites 
Viscum. 268. 
— Pis not parasitic, growing on the ground . . 3 
3. Small leafless shrubs, with articulate branches 
Ephedra. 667. 
— Leafy trees or shrubs. 1 
4. Resinous trees or shrubs (the ls resembling those of 
firs) ......... 5 
