OF PLANTS CALLED COMPOSITE. 297
Obs. In Yon Rohr's natural character of Melanthera the Nectarium, or glandular body sheathing the base of the style, is introduced, which is the earliest notice I [us have yet found of this organ in Compositae, except in Eatsch's Analysis Florum, published in 1790, where it is both described and figured in Coreopsis tripteris. The merit, however, of establishing its nearly universal exist- ence in the hermaphrodite florets of this extensive class belongs to M. Cassini.
Both Von Rohr and Richard in their characters of Mela- nanthera have described the antherae as shorter than the corolla, which is indeed the case in a particular state of the flower ; immediately after its expansion, however, they project considerably, and again become inclosed in the more advanced stage. This fact has been noticed by Jac- quin, 1 who considers the final inclosure of the antherae to be owing to the elongation of the corolla. But the actual increase in length of the corolla is very slight, and by no means sufficient to account for the appearance; the real cause of which is a considerable, and I believe a gradual, contraction of the filaments. This economy is not unfre- quent in Compositae, especially in the tribe of Ilelianthece, [no to which Melananthera belongs.
In M. Cassini's Memoir on the Stamina of Compositae the retraction of antherae is not expressly noticed. This
ripe seeds only, it would certainly have been referred to it. The following characters, however, prove it to be sufficiently distinct. It may be named
Lipotriche.
Involucrum duplici serie imbricatum, subsequale. Receptaculum convexum, pa lets foliaceis, distinctis. Capitulum radiatum. Lignite (simplici serie) feminese. Flosculi hermaphroditi, stigmatibns appendice acuto hispidulo. Achenia subuniformia, turbinata ; Pappo setaceo, caduco.
Herbse (Africse eequinoctialis) Folia opposita, indivisa. Pedunculi terminates, term. Iuvolucra brevia, foliacea. Paleae receptaculi carinatee, nervosa, acuta Corollulse flavee. Ligulee elongates, Z-dentatee. Antherse nigricanf.es, sub- inclusee, bast muticee. Achenium obtuse tetragonum. Pappus, in disco verticis depressi, brevis, e setulis simplici serie, numerosis (8 — 10), distinctis, dentieulaii*, caducis vel deciduis.
Melanantherse proximo accedit : affinis quoque Ecliptre Linn. Wedelia Jacq. et Diomedese Cassini (in Journ. de Phys. tome lxxxii, p. 145), sed ab his omnibus satis distincta videtur.
1 Collect, ii, p. 291, Ic. Rar. iii, t. 583.
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