454 
The Ohio Naturalist. 
[Vol. IX, No. 4, 
42. Ginkgoeae. Maiden-hair-trees. 1 living species. 
Sporophytes developing into large trees with a cambium layer 
from which annual rings of wood are produced, with numer¬ 
ous, large, wart-like dwarf branches on the ordinary branches; 
leaves deciduous, broad, with dichotomous venation, borne in 
clusters on the dwarf branches or alternate on ordinary branches; 
flowers monosporangiate, dioecious; ovule with pollen-chamber; 
cotyledons, 2, the embryo not developing until the seed falls to 
the ground; female gametophvte becoming large in the seed 
which has a bony inner and a fleshy outer coat; male gameto- 
phvte developing 2 large spirally coiled multiciliate sperma- 
tozoids. 
43. Coniferae. Conifers. 350 species. 
Sporophytes developing as shrubs or large trees, much 
branched, with or without dwarf branches; stems with a normal 
cambium, no vessels in the secondary wood, resin nearly always 
present; leaves mostly small, entire, linear, lanceolate, subulate, 
or scale-like; flowers monosporangiate, monoecious or dioecious; 
seeds and female gametophyte rather small, ovules without pol¬ 
len-chamber, cotyledons 2-15, always free; sperm cells 2, not 
motile, no cilia being present. 
44. Gneteae. 50 species. 
Sporophytes developing as shrubs, trees, or woody climbers, 
with branched or simple stems containing vessels in the second¬ 
ary wood; leaves simple and opposite; flowers monoecious; seeds 
naked, orthotropous; cotyledons two; resin passages none; 
gametophytes various. 
VII. ANGIOSPERMAE. 125,000 species. 
45. Monocotylae. Monocotyls. 24,000 species. 
Sporophvtes developing as herbs or sometimes as woody 
plants of large dimensions, embryo usually with one terminal 
cotyledon and usually with a lateral plumule; stem with closed, 
usually scattered vascular bundles, without typical bark and 
annual rings of growth, rarely with secondary thickening; leaves 
mostly parallel-veined, sometimes netted-veined; flowers more 
commonly trimerous. 
Subclasses, Helobiae 
Spadiciflorae 
Glumiflorae 
Liliiflorae 
46. Dicotylae. Dicotyls. 100,000 species. 
Sporophytes developing as herbs or woody plants; embryo 
with two cotyledons, rarely with more or only one, and with a 
terminal plumule; stem with open vascular bundles, usually 
