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 gametophyte becoming large in the seed 

 which has a bony inner and a fleshy outer coat; male gameto- 

 phyte 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. 

 Sporophytes 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, 

 usuallv 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 



Ghimiflorae 



Lilii florae 



40. 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 



