. The natural history of plants. Botany. RHAMNAGEM. 63 Colletia is one ovule inserted at the base of the internal angle, with micro- pyle ascending and at first directed downwards and inwards but, as in Ehamnus, ultimately becoming more or less decidedly lateral.^ The fruit, accompanied at the base by a receptaeular cupule,'^ is a drupe, with thin mesocarp, finally dry, and formed of three cocci which separate and open in two valves to liberate each an albuminous seed, analogous to that of the Buckthorns, plano-convex, with a crustaceous testa. Colletia consists of shrubs from the t
. The natural history of plants. Botany. RHAMNAGEM. 63 Colletia is one ovule inserted at the base of the internal angle, with micro- pyle ascending and at first directed downwards and inwards but, as in Ehamnus, ultimately becoming more or less decidedly lateral.^ The fruit, accompanied at the base by a receptaeular cupule,'^ is a drupe, with thin mesocarp, finally dry, and formed of three cocci which separate and open in two valves to liberate each an albuminous seed, analogous to that of the Buckthorns, plano-convex, with a crustaceous testa. Colletia consists of shrubs from the temperate and cool regions (espe- cially the western) of South America, often leafless or with very small leaves decussate, as also the axillary branches, often thickened, spinescent, vertically flattened and generally nearly triangular.^ The flowers, axillary and solitary, or collected in few-flowered cymes, are situated under these axillary branches. A dozen species* are known. Formerly the genus included a much larger number ; but it has recently been dismembered of a number of secondary genera which in other respects scarcely possessed the value of a section. Sometimes it happens that, the fruit separating into cocci as in Colletia, the disk is attached in the form of a cupule to the bottom of the perianth, and that the opposite and spinous branches are articu- late, as in Discaria, natives of South America, New Zealand, and Australia; or the floral receptacle, lass deep and obconical, its concavity lined with the disk, supports an open perianth with independent folioles, as in Adolphia infesta, a subaphyllous American shrub, with opposite and articulate spinous branches. In Retanilla, Chilian and Peruvian shrubs, spinous and leafless, the diminishing disk ascends the internal surface of the perianth, and the fruit is a drupe with a 1-3-celled putamen. The same fruit is observed in Talguenea and Trevoa, also from South America, but Figi 57. Long. sect, of flower (^). ' A dou
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectbotany, bookyear1871
