6 SUPPLEMENT. 
(inetums are woody vines or lianas; Ephedra consists of erect shrubs 
with green or yellowish articulated branches quite destitute of leaves, 
while the peculiar Tumboa has a short trunk only a foot high, but 
several feet in diameter, from which depend two long strap-shaped 
leaves of so firm a texture that they endure for many years. The 
Gnetales possess no economic and little ornamental value. The young 
herbage and the berry-like fruit of Getum Gnemon is said to be eaten 
as a vegetable in India. : 
ORDER CYCADALES. (Fic. 3.) 
This order, like the last, is restricted to a single family, the Cy- 
cadacee or Cycad family. The group is of special interest to the 
botanist, in view of the peculiar method by which fertilization is ef- 
fected, mention of which has been inade above. Cycads were abundant 
in prehistoric time, as is evidenced by the large quantities of well-pre- 
served trunks found in the cretaceous deposits. in Maryland and other 
localities, The genera are nine in nuwber. Of these, two are Mexi- 
can, one Cuban, two African, one Australian, and the remainder. are 
distributed through the tropics of both hemispheres. The genus Cycas 
has a well known representative in cultivation, Cycas revolutu of Japan, 
It is palm-like in appearace, having a thick short trunk and a crown of 
of handsome pinnate leaves of firm texture. Zamia is represented by 
two native species in Florida, where they are known as the coontie or 
Florida arrowroot. They are low plants, rarely exceeding a foot in 
height, and cover large tracts in the dry barrens. The leaves are not 
unlike those of a coarse brake or fern, and the thick erect, mostly sub- 
terranean stems abound in starchy matter from which a very good 
grade of arrowroot is obtained, 
The inflorescence of Cycads is dieecious, like that of the Gnetads. 
The male and female flowers are produced separately in dense cones, and 
consist merely of anthers and ovules without any perianth, borne on 
thick scales. The seeds are either hard or with spongy. outer cover- 
ing. Although our cultivated cycads and the native species of Zamia 
above referred to are dwarf plants, yet in tropical regions members of 
this group are often tall in stature, with unbranched trunks resembling 
those of palms, and large crowns of pinnate leaves. 
