io6 
The Ohio Naturalist. 
[Vol. XIII, No. 6, 
II. Leaves simple or merely lobed, venation dichotomous or parallel; stems 
with numerous branches forming a dense crown. 
1. Without dwarf branches; leaves usually elongated, with parallel 
veins. (Fossil.) Cordaite.e CORDAITALES. 
2. With thick wart-like dwarf branches; leaves fan-shaped, entire or 
lobed, sometimes deeply divided, deciduous. 
Ginkgoe.e. GINKGOALES. gixkgoace.e. Ginkgo. Maiden-hair-tree. 
Synopsis of the Cycadales. 
I. Megasporophylls (carpels) leaf-like, arranged in a rosette through 
which the main stem continues its growth; seeds 8—4, seldom 2, 
horizontal or erect; leaflets with a midrib; cortical cauline vascular 
bundles present. cycadaceze. Cycas. 
II. Megasporophylls (carpels) highly specialized, arranged in lateral 
cones; seeds 2, inverted; pinnae parallel-or feather-veined, zamiace^e. 
1. Cortical cauline vascular bundles present, forming several wood 
zones. MACROZAMIAT/E. 
(1) . Leaves simply pinnate. 
a. Carpels pointed. Macrozamia. 
b. Carpels shield-shaped. Encephalartos. 
(2) . Leaves doubly pinnate; stem subterranean. Bowenia. 
2. Cortical bundles absent; primary cambium persistent, zaxiiat.e. 
(1) . Leaflets feather-veined. Stangeria. 
(2) . Leaflets parallel-veined. 
a. Ovules on a process of the carpel; carpel pointed and 
leaf-like. Dioon. 
b. Ovules sessile; carpels shield-like. 
(a) . Carpels shield-like, not horned. 
((a)). Tree-like when mature; carpellate cones 2-3 
ft. long. Microzamia. 
((b)). Usually' with a low tuberous stem or geophi- 
lous; carpellate cones much smaller. Zamia 
(b) . Carpels 2-horned. Ceratozamia. 
Synopsis of the Strobilophyta. 
I. No vessels (enlarged tracheids) in the secondary wood; wood frequently 
with resin ducts; cotyledons 2-15. Conifer.e. 
1. Carpels usually numerous, in strobili (cones); seeds covered by the 
carpel tips or by ovuliferous scales; cones rarely becoming fleshy 
when mature; seeds dr> T , the testa woody or leathery. PINALES. 
(1) . Leaves spirally arranged. 
a. Pollen wingless; carpels with one to several seeds; ovu¬ 
liferous scale not prominent, or none. 
(a) . Carpel with one seed; microsporangia 5-8, free and 
pendulous, araucariace.e. 
(b) . Carpel with two to nine seeds; microsporangia 2-5. 
TAXODIACE.E. 
b. Pollen grains winged; carpels with two inverted seeds; 
ovuliferous scales prominent; plants monecious. 
PINACE.E. 
(2) . Leaves opposite or whorled. juniperace.e. 
2. Carpels of the cone few or 1; seeds with fleshy' testa or covered by' a 
fleshy aril. TAXALES. 
(1) . Stamens with 2 microsporangia; pollen winged; seed 1. 
a. Not with phylloclades. podocarpace^e. 
b. With phylloclades. phyllocladace.e. Phyllocladus. 
(2) . Stamens with 3-8 microsporangia, seeds 1 or 2, erect, pollen 
wingless. taxace/E. 
