8 PLANTiE FRjblONTIAPf^E I. 



limb. The leaves are four-ranked, as usual in this genus, very small, and closely- 

 imbricated ; their bases prolonged downward and contracted, with strongly-marked 

 longitudinal lines where the two exterior overlap the two interior ones. In the 

 younger branchlets, the decurrent bases are from two to three times longer than their 

 diameter, and in the older ones, about four times longer. None of the leaves are 

 acerose. The two interior of each joint are marked on the face with a slight 

 depression, beneath which there is often a small obscure gland, although none 

 appears externally. The staminiferous aments terminate the branchlets. They are 

 ovoid-oblong, and from two to three lines in length. The stamens are from twelve 

 to fourteen, four-ranked ; the connective produced into a suborbicular excentric- 

 ally peltate scale, and bearing on its under surface about four oblong anther-cells, 

 which open longitudinally. The seminiferous aments are nearly an inch in length, 

 ovate-oblong, and consist of four scales, of which the two exterior are very short, 

 the two interior rounded externally, with the flattened septum-like axis prolonged 

 between them, and equalling them in length ; all the scales mucronate with a short 

 recurved point below the tip. Beneath each interior scale are two seeds. These 

 are furnished with two very unequal wings. 



This tree much resembles Callitris quadrivalvis in its foliage. It has pro- 

 bably been confounded by some botanists with Thuya gigantea of Nuttall, from 

 which, however, it can be distinguished by the foliage alone ; the long decurrent 

 bases of the leaves being characteristic of the Libocedrus. Endlicher has 

 described three other species of this genus, all of which are natives of South 

 America and New Zealand. Our L. decurrens is most nearly related to 

 L. Chilensis Endl. (Thuya Chilensis Hook. Lond. Jour. Bot. 2. p. 199. t. 4.) 



COLEOGYNE. Nov. Gen. 



Calyx basi bibracteolatus, coriaceus, petaloideus, quadrisepalus ; sepalis basi 

 connatis persistentibus. Corolla nulla. Stamina numerosa ; filamentis ima basi 

 disci tubaeformi inserta. Ovarium uniovulatum, uniloculare, tuba disci inclusum 

 ovulum hemitropum : stylus lateralis, filiformis, intus longitudinaliter stigmatosus. 

 Fructus . . . — Frutex Californicus, ramosissimus, rigidus ; ramulis saepe 

 subspinescentibus ; foliis parvulis, oblongis, crassis, oppositis, confertis, brevissime 

 petiolatis ; lamina decidua, stipulis cum petiolo minutissimo persistentibus ; floribus 

 solitariis, terminalibus, basi bracteis trifidis suffulti. 



COLEOGYNE RAMOSISSIMA. Tab. IV. 



Hab. Sources of the Mohave and Virgin Rivers, tributaries of the Colorado of 

 the W est, in the mountains of Southern California. Flowering in April and May. 



A shrub with the aspect of Krameria, five to six feet high, and clothed with a 

 grayish bark ; the branches spreading, short, crowded, and mostly opposite. 



