xviii GENERA. 



Gen. AcTiNOSTEOBUS, Miguel. Leaves in whorls of three, very 

 small, scale-formed, persistent, and very acute-pointed. 



Flowers, male and female on the same plant, but 

 separate. 



Cones globular, woody, and composed of six scales, 

 disposed in two vertical sets at the base. 



Seeds in twos under each of the upper scales, three- 

 edged, and winged on each side. 



Sec. II. TAXODI^. Cones with the scales spirally disposed. 



Gen. Gltptostrobus, EndUcher. Leaves scattered, spreading, 

 variously shaped, and trigonal or subulate. 



Flowers, male and female on the same plant, but 

 separate. 



Cones egg-shaped or oblong, and composed of several 

 unequal-siaed scales, all rising from the base, and of a 

 leathery texture. 



Seeds in twos and winged, or wingless. 



Gen. Taxodium, Bicliard. Leaves linear, two-rowed, and de- 

 ciduous. 



Flowers, male and female on. the same plant, but 

 separate. 



Cones globular, woody, and with the scales shield- 

 shaped. 



Seeds irregularly shaped, wingless, woody, and in 

 twos. 



Gen. Sequoia, EndUcher. Leaves linear, flat, persistent, and 

 spread out in two rows horizontally. 



Flowers, male and female on the same plant, but 

 separate. 



Cones small, globular, and woody, with peltate, wedge- 

 shaped scales, having a spiny point in the centre. 



Seeds mostly in threes under each scale, variously 

 shaped and winged. 



