April, 1913.] 
The Classification of Plants, IX. 
107 
II. Vessels -present in the secondary wood; wood without resin ducts; 
embryo with 2 cotyledons; strobili in specialized inflorescences; leaves 
opposite. Gnete^e. 
1. Archegonia well developed; primary cambium persistent; leaves 
scale-like; stem green and fluted. 
EPHEDRALES. ephedrace.®. Ephedra. 
2. Archegonia reduced; concentric cortical series of vascular bundles 
produced; leaves ribbon-like or broad. GNETALES. 
a. Leaves only 2, ribbon-like and split when old; stem tuber¬ 
ous. tumboacejj . Tumboa (Welwitschia). 
b. Leaves numerous, broad, netted-veined. 
gnetacejs. Gnetum. 
Synopsis of the Families of Conifer.e With More Than One Genus. 
araucariace.e. 
1. Seed without a wing, coalesced with the carpel. Araucaria. 
2. Seed winged, free from the carpel. Agathis. 
TAXODIACEHi. 
I. Dwarf branches; if any, and the leaves not all deciduous at the same 
time. 
1. Not with true dwarf branches. 
(1) . Ovules or seeds 3; carpellate cones often clustered at the 
end of the twig; leaves rather broad. Cunninghamia. 
(2) . Ovules or seeds, 2, or more than 3, if 3 then the carpellate 
bract toothed; leaves rather narrow or scale-like. 
a. Microsporangia on the stamen 3-6. 
(a) . Carpellate bract not toothed. 
((a)). Seeds 2; carpellate cones Y 2 in. long. 
Taiwania. 
((b)). Seeds -4—9; carpellate cones 1 in. or more in 
length. Sequoia. 
(b) . Carpellate bract toothed; seeds 3-6. Cryptomeria. 
b. Microsporangia on the stamen 2; carpel with 4-9, mostly 
5 seeds. Arthrotaxis. 
2. Dwarf branches extending into a long double needle; microsporangia 
2, seeds about 7. Sciadopytis. 
II. Dwarf branches deciduous; carpel shield-like, ovules 2. 
1. Ripe carpels persistent. Taxodium. Bald-cypress. 
2. Ripe carpels deciduous. Glyptostrobus. 
pinace^e. 
I. Without dwarf branches. 
1. With sterigmata; carpels persistent. 
(1) . Carpellate bracts longer than the ovuliferous scales; leaves 
flat. Pseudotsuga. Douglas-fir. 
(2) . Carpellate bracts shorter than the ovuliferous scales. 
a. Leaves prismatic, carpellate cones drooping. 
Picea. Spruce. 
b. Leaves flat. 
(a) . Carpellate cones drooping. Tsuga. Hemlock. 
(b) . Carpellate cones erect. Keteleeria. 
2. Without sterigmata, carpels deciduous; carpellate cones erect; 
carpellate bract longer than the ovuliferous scale; leav T es mostly 
flat. Abies. Fir. 
