VI 



KEY TO THE FAMILIES. 



Inflorescence a fleshy spadix. 

 Inflorescence not a fleshy spadix. 



Perianth none, or of bristles, chaffy scales 

 or a hyaline envelope. 

 Flowers in the axils of chaffy bracts. 

 Stems mostly hollow, jointed; leaves 



2-ranked. 

 Stems solid; leaves 3-ranked. 

 Flowers not in the axils of chaffy bracts. 

 Perianth herbaceous or none. 

 Carpels 1-5, separate. 

 Carpels 3 or 6, united into a com- 

 pound ovary. 

 Perianth of bristles or chaffy scales. 

 Flowers in terminal cylindrical 



spikes. 

 Flowers in axillary globular heads. 

 Perianth present, the parts glume- or petal- 

 like. 

 Perianth of glume-like segments. 

 Perianth at least in part petal-like. 

 Carpels distinct. 

 Carpels united. 

 Ovary superior. 



Flowers more or less irregular, 



surrounded by a spathe. 

 Flowers regular, without a 

 spathe. 

 Ovary inferior. 



Aquatic plants; flowers dioe- 

 cious or polygamous. 

 Terrestrial plants ; flowers 

 perfect. 

 Flowers regular. 

 Flowers irregular. 



Araceae, 85. 



Poaceae, 31. 

 Cyperaceae, 65. 



Najadaceae, 25. 

 Scheuchzeriaceae, 29. 



Typhaceae, 23. 

 Sparganiaceae, 24. 



Juncaceae, 87. 

 Alismaceae, 30. 



Pontederiaceae, 86. 

 Liliaceae, 92. 



Hydrocharitaceae, 30. 



Iridaceae, 104. 

 Orchidaceae, 106. 



Sub-class DICOTYLEDONES. 



I. Petals Distinct to the Base or Wanting. 

 A. Petals None. 



Plants parasitic or saprophytic and usually with- 

 out chlorophyll. 

 Flowers dioecious; stamens 2-6. 

 Flowers perfect; stamens 10. 

 Plants neither parasitic nor saprophytic but hav- 

 ing chlorophyll. 

 Trees or shrubs. 



Leaves small, linear or scale-like; plants 



heath-like. 

 Leaves large; plants not heath-like. 

 Leaves opposite. 



Leaves silvery-scurfy. 

 Leaves not silvery-scurfy. 

 Fruit a drupe. 

 Fruit a samara. 



Loranthaceae, 122. 

 Allotropa, 271. 



Empetraceae, 232. 



Elaeagnaceae, 244. 

 Garrya, 269. 



