volucrum distinct and entire, differs from it in having its calyx 5-fid with sharp sinuses, in the absence of glands, in the reduced number of stamina, and in its dispermous ovaria.
3. Tribulus {Hystrix) lanatus, foliis 8-10-jugis, fructibus undique tectis spinis subulatis longitudine inæqualibus: majoribus sparsis longitudinem cocci superantibus.
Loc. "In collinis arenosis. Lat. 26°." D. Sturt.
Desc. Herba diffusa, sericea, incana. Folium majus cuiusque paris 8-10-jugum, foliolis ovatis. Flores magni. Calyx æstivatione leviter imbricatâ. Petala calyce duplo longiora. Stamina decem, antheris linearibus.
Obs. I a species nearly related to T. Hystrix, found on the west coast of Australia, or on some of its islands, in the voyage of the Beagle, may be distinguished by the following character. Tribulus (occidentalis) sericeo-lanatus, foliis suboctojugis, coccis undique densè armatis: spinis omnibus conico-subulatis longitudine invicem æqualibus. These two species difter from all others in the uniform shape of the spines, which equally cover the whole external surface of the fruit.
Obs. II. The American species of the Linnean genus Tribulus are distinguishable from the rest of the published species, by having ten monospermous cocci, by their persistent calyx, and the absence of glands subtending the 5 filaments opposite to the sepals.
This tribe was originally separated as a genus by Scopoli, under the name of Kallstrœmia, which has been recently adopted by Endlicher.
Another tribe exists in the intratropical part of the Australian continent, to which, nearly 40 years ago, in the Bank- 70] sian Herbarium, I gave the generic name of Tribulopis and which may readily be distinguished by the following characters.
