370 Mr. J. Miers on the Tribe Colletiese. 



XL. — On the Tribe Colletiese, with some Observations on the 

 Structure of the Seed in the Famihj of the Rhamnacese. By 

 John Miers, F.R.S., F.L.S. &c. 



[Continued from p. 273.] 



Division 2. Chaenocarpse. Flores petaliferi ; fructus capsularis, 

 dehiscens. 



3. DiSCARIA. 



This genus was first established by Sir W. Hooker in 1830, 

 and was then distinguished from Colletia principally on account 

 of its smaller, cup-shaped, hypogynous disk, having an entire 

 border, and not being perigynous, with a very remarkable invo- 

 lute margin : this, and the presence of petals, were well-marked 

 characters; but these exist also in other genera since then 

 established, which are again signalized by other distinct features. 

 The several species of Discaria, with two exceptions, seem to be 

 limited to a region formed by the provinces which border the river 

 Plate : they are all spinose in their habit, much resembling in 

 appearance those of Colletia, and consist of undershrubs or low 

 bushes, almost aphyllous, and generally glabrous. The peculiar 

 character which distinguishes this genus from Ochetophila is that 

 of its fruit, which here also is capsular, somewhat globular, and 

 3-lobed, and half imbedded in the enlarged fleshy disk conjoined 

 with the strongly ribbed cupular base of the calyx. I have 

 pointed out in Colletia the easy decortication of the upper por- 

 tion of the epicarpous covering, which, at the period of dehis- 

 cence, breaks away by a transverse circumscissile line ; here, on 

 the contrary, where it is thicker in texture, and half coriaceous, 

 it opens by radiating lines into three valves, which generally 

 remain persistent upon the margin of the disk, and thus allow 

 its three enclosed cocci to spring out and escape. The support 

 of the fruit appears formed of two thickened adnate cups ; the 

 inner one, somewhat the longer, is the enlarged disk, surrounded 

 by the detruncated base of the calyx, while in Ochetophila this 

 appearance does not occur, as there the basal support is thin 

 and almost membranaceous, and the disk, not exceeding the 

 length of the calycine cup,. is not manifest. For reasons assigned 

 in their respective places, the following species, formerly placed 

 ' here, aire referred to other genera : D. australis, Hook., to Oche- 

 tophila; D. paucijiora, Hook, fil., to Scypharia; and D. Touma- 

 tou, Raoul, as already described, to Notophana. 



Discaria, Hook. — Calyx tubuloso-campanulatus, 8-10-nervis, 

 lirnbi laciniis 4-5, acutis, reflexis, testivatione valvatis, imo 

 dcmum circumscissus. Petala 4-5, squamiformia, ovata, un- 

 guiculata, subconvexa, stamina amplectentia. Stamina 4-5, 



