'126 NATURAL HISTORY OF PLAKT8. 



have been made into a special tribe (JmperecB), principally on account 

 of the semi-cyliadrical form of their cotyledons, nearly equal in size 

 to their radicle. Their calyx is valvate in the male flower, and imbri- 

 cated in the female, as in most of the preceding genera. The diplo- 

 stemonous androceum is formed of stamens, whose anthers, with 

 wall-shaped cells, much recall those of our indigenous Mercuriales; 

 it is sometimes surrounded by a disk with elongate glands. Cali/- 

 copeplus^ formerly ranked among the EuphorUacea^ has the spartoid 

 habit of Jmperea, opposite glandtdar leaves very little developed, 

 and flowers also in cymes. The terminal flower is central and com- 

 posite, as in Amperea, having a trimerous gynseceum, with uniovu- 

 late cells and a perianth with six divisions ; the male flowers, dis- 

 posed in biparous cymes, are peripherical, each reduced to a small 

 perianth and one single stamen, with anther looking outwards. 

 Cnesmone Javanica, a climbing shrub with large leaves covered 

 with hairs, has only an isostemonous androceum, in the male 

 flowers apetalous and trimerous. The female flower is, on the con- 

 trary, nearly that of Jmperea, presenting a trimerous gyneeceum, 

 surrounded by an imbricated calyx. The anthers are surmounted 

 by a long prolongation of the connective, a kind of articulate rod, 

 incurved- geniculate, which, in the bud, folds itself within on the face 

 of the anther. This organ does not exist in Tragia, which has the 

 same perianth as Cnesmone^ with a number of pieces varying from 

 three to eight in the female flower, where it is imbricated. The 

 stamens are equal in number to the pieces of the perianth with which 

 they alternate, or fewer in number (so that with three sepals there 

 are only two or one stamen), or even, again, double in number or 

 indefinite, on several verticils, with extrorse or introrse anthers. 

 In the latter case they are accompanied by a variable number of 

 glands. Tragia consists of volubile hispid plants from all warm 

 climates, principally tropical America. In Zuckertia, a Mexican 

 bind-weed, nearly allied to Tragia, the flowers are eglandular, the 

 male calyx is pear-shaped in the bud, and the stamens, indefinite 

 in number, form a large central bundle. The filaments are united 

 quite at the base, and the elongated anthers are extrorse. The three- 

 celled ovary, surrounded by a variable number of ,sepals, is sur- 

 mounted by a style whose common basilar part is swollen into a 

 club before separating into three revolute branches. LeptoracMs, 



