6 



KEY TO SEED PLANTS. 



Flowers (in ours) pedicellate, in paniculate clusters, or subsessile 

 in dense capitate heads: perianth of 6 distinct dry segments; 

 leaves terete or flat; fruit a capsule. . Juncacej?, p. 92. 



B. Flowers on a spadix or spike, the whole cluster often enclosed by 

 a spathe or foliaceous or membranaceous bract; perianth none or 

 not petal-like. 



Subaquatic reed-like plants: flowers unisexual, borne in a dense 



cylindrical spike or globose head, without distinct perianth . . 



Typhace.e, p. 95. 

 Small or minute leafless aquatics, the stems represented by leaf-like 



floating fronds Lemnace.e, p. 97. 



Aquatic plants; flowers naked or with a very small calyx, perfect 



or unisexual; stamens 1 to 4 . . . . . Naiadace^e, p. 99. 

 Marsh or subaquatic plants; flowers perfect, with or without 



perianth; stamens 6 or 1 Juncaginace^s, p. 102. 



C. Flowers with a more or less corolla-like perianth. 



Ovaries several, distinct, becoming achenes in fruit; perianth of 3 



sepals and 3 petals Alismace^e, p. 104. 



Ovaiy 1 and 



Superior; perianth regular, petal-like; stamens 6, sometimes 



3 or 4 Liltace^e, p. 106. 



Inferior. 



Perianth regular; stamens 3 Iridace^e, p. 128. 



Perianth irregular; stamens 1, rarely 2. Orchidaceje, p. 130. 



CLASS 2.— DICOTYLEDONS. 



Leaves netted-veined; parts of the flower mostly in 4's or 5's; vascu- 

 lar bundles in a ring around a central pith, the stem when 

 perennial increasing in girth by annual layers; embryo with 2 

 cotyledons. 



I. APETALOUS DIVISION. Corolla none: calyx present, some- 

 times petal-like, rarely none. 



A. Flowers monoecious or dioecious, one or roth kinds in 



AMENTS; TREES OR SHRUBS. 



Leaves simple and 



Opposite; flower dioecious, 1 to 3 in each axil of the connate bracts; 

 sepals of staminate flowers 4, of pistillate flower 2 or none . . 



Garryace^e, p. 362. 



Alternate. 



Both kinds of flowers in aments. 



Flowers 1 to each scale or bract; perianth none. 



Fruit a 1 -celled many-seeded capsule; seeds with a coma; 



flowers dioecious . Salicaceje, p. 135. 



Fruit a waxy-coated berry; flowers monoecious or dioecious. 



M yric acEjE, p. 14G. 

 Flowers 2 or 3 to each scale or bract; staminate anient long, 

 pendulous; pistillate small, maturing into a woody cone 

 containing margined achenes. , . Bktulace;k, p. 139. 



