18 Karl M. Wiegand and Arthur J. Eames 



PAGE 



j. Flowers not in heads, or if so then perfect. 



k. Flowers axillary, solitary, with a 2-lobed truncate or 



retuse ovary Callitrichaceae 290 



k. Flowers spicate, or if axillary then the ovary not as 



above Najadaceae 46 



h. Submerged leaves palmately or dichotomously dissected. 



Ceratophyllaceae 205 

 g. Plants not truly aquatic, part of the stem or leaves raised above 

 the surface of the water. 

 h. Herbs. (2d h, p. 19.) 

 i. Flowers in dense fleshy greenish spikes (spadix) which are 

 usually subtended by a spathe; perianth present or absent. 



Araceae 134 

 i. Flowers in dense unisexual spikes, each minute floret sub- 

 tended by bristles Typhaceae 44 



i. Flowers in long slender white nodding spikes ; perianth 



wanting Piperaceae 161 



i. Flowers not in spikes, or if so not as above. 

 j. Perianth with three parts united into a crested organ. 



Polygalaceae 286 

 ;'. Perianth with parts not united into a crested organ. 

 k. Ovary 1, 1-celled (rarely 2-celled in Sparganiaceae). 

 /. Ovule 1. 



m. Stipules sheathing ; fruit lenticular or sharply 3- 



angled Polygonaceae 185 



m. Stipules not sheathing, often wanting; fruit not as 

 above. 

 n. Leaves parallel-veined, linear ; monoecious mono- 

 cotyledons Sparganiaceae 44 



n. Leaves netted-veined ; dicotyledons. 



o. Style or stigma 1 Urticaceae 180 



o. Styles or stigmas 2-5. 



p. Leaves deeply palmately cleft or compound. 



Cannabis 182 

 and Humulns 182 

 p. Leaves pinnately lobed, serrate, or entire. 

 q. Stipules, if any, not scarious. 

 r. Flowers in dense scarious-bracted and 



often spiny clusters. . . Amaranthaceae 196 

 r. Flowers often in dense clusters but not 

 scarious-bracted ; often mealy. 



Chenopodiaceae 193 



q. Stipules scarious Illecebraceae 197 



/. Ovules several or many. 

 m. Leaves elliptic-linear. 

 n. Placenta free-central ; leaves rather soft. 



Caryophyllaceae 198 



n. Placentae parietal ; leaves firm Cistaceae 301 



»;. Leaves oval, suborbicular, or pinnatifid. 

 n. Plants more or less creeping, in wet places ; flowers 



small, greenish; juice colorless. .Chrysosplcnium 238 

 ;;. Plants erect, in drier places; flowers larger, white 

 or yellow (calyx caducous, flowers therefore 

 appearing apetalous) ; juice colored. 



o. Placentae 2-5 Papaveraceae 220 



o. Placenta 1 Berberidaceae 218 



