CONTRIBUTIONS TO BOTANY. 
285 
Division 3. Clithrocarpse. Flores petaliferi; fructus nucamen- 
taceus et lignosus aut membranaceus, fere semper indehis- 
cens. 
6. Retamilia. 
This genus is very distinct from all others of this tribe, dif- 
fering in its peculiar virgate habit, its almost aphyllous Ephedra- 
like erect branches ; the reduction of its disk to the size of a mere 
torus, or stipitate support of the ovary ; and its large, spherical, 
thick, nuciform fruit. The name of Retanilla was first applied 
(in 1825) by DeCandolle, in his Prodromus (ii. 28), to a section 
of the genus Colletia, under which he arranged two plants, di- 
stinguished from others of that genus by the presence of petals 
and the absence of the conspicuous disk : these were the Rhum- 
nus Retamilia and Rhamnus Ephedra of Dombey, both collected 
by him in Chile, — Ventenat having previously described both 
plants as species of Colletia. Brongniart (in 1827) adopted the 
suggestion of DeCandolle, in his Monograph of the Rhamnacece, 
and established the genus Retanilla for the same plants, making 
the type of his genus the Colletia obcordata, Vent, (identical 
with Rhamnus Retamilia, Domb.). 
There has been an error, originating with DeCandolle (Prodr. 
li. 28), in converting Dombey^s Spanish name, Retamilia, into 
Retanilla, the former being the diminutive of Retama, or com- 
mon Broom of Europe, which resembles the Chilean plant in its 
almost leafless virgate stems; but, as the Spanish ll has inva- 
riably a liquid pronunciation, it is desirable to correct the spell- 
ing in harmony with it, and thus Retamilia becomes the more 
appropriate name. One of the peculiarities of the genus con- 
sists in the structure of its fruit, which is much larger than in 
any other genus of the tribe, is somewhat drupaceous, with a 
fleshy epicarp that becomes coriaceous, and incloses a hard, 
ligneous, indehiscent nut, the partitions between its cells being 
very thick and woody ; it is smooth, with three slight furrows, 
corresponding with the lines of the dissepiments ; the trans- 
verse disposition of the woody fibres of the thick endocarp ap- 
pears a constant character, worthy of notice. As previously 
mentioned, Brongniart quotes this as one of the few genera of the 
RhamnaceeE in which stipules are wanting ; but in all the speci- 
mens I have seen they are certainly developed in the manner 
peculiar to most of the Colletiea. The generic character is 
emended in the following manner ; — 
Retamilia, Brongn. Molinaa,Comm. — C'a/y,z’ tubuloso-campa- 
nulatus, carnosulus, limbo 4-5-fido, laciniis triangularibus, 
erectis, intus carina calloque apicali notatis, lestivatione val- 
