Melampodium. composite. 271 



Div. 1. Melampodie^j, DC. — Fertile and sterile flowers in the 

 same heads ; the former several, ligulate ; the latter central, tubular. Ache- 

 nia corticate* (that is, invested and concrete witli the scales of the involucre 

 or chaff of the receptacle). Pappus none. Anthers united. 



69. MELAMPODIUM. Linn.; Gartn.fr. t. 169; R. Br. in Linn, 

 trans. 12. p. 104. 



Heads many-flowered ; the ray-flowers 5-10, in a single series ; those of 

 the disk sterile Ly the abortion of the style. Involucre double ; the exterior 

 of 3-5 flat and spreading foliaceous scales; the inner as many as the ray- 

 flowers and enclosing their achenia. Receptacle convex or subulate-conical, 

 chaffy; the chaff membranaceous, deciduous. Style in the sterile-flowers 

 undivided and hairy above. Achenia of the disk abortive ; of the ray ob- 

 ovoid, smooth, slightly curved, invested by the inner scales of the involucre, 

 which are often rugose or tuberculate, or cucullate at the summit, and either 

 truncate or produced into 1-3 teetli or awns. — Herbaceous or suffruticose 

 (chiefly Mexican) plants, with dichotomous stems, opposite sessile leaves, 

 and terminal or alar peduncles bearing a single head. Flowers yellow, or 

 the rays rarely (in two species?) white. 



1. M. ramosissimum (DC): stem slightly suffruticose, much branched, 

 glabrous ; leaves linear, pubescent with somewhat appressed hairs, entire, or 

 remotely dentate-lobed or sinuate ; peduncles longer than the leaves; rays 

 oblong-linear, small (yellow) ; exterior scales of the involucre oval, pubes- 

 cent externally ; the interior involving the achenia, tuberculate at the base, 

 the summit expanded into a broad hood, with a dorsal uncinate acumination. 

 DC! prodr. 5. p. 518. 



Texas, Berlandier ! (v. sp. in herb. DC.) 



2. M. leucanthum: suffruticose, much branched at the base, strigose 

 throughout and dotted with minute resinous globules; leaves very numerous, 

 linear, the lower linear-spatulate, obtuse, entire, strigose-hispid above ; pe- 

 duncles much longer than the leaves ; rays oval-oblong, emarginate, thrice 

 the length of the ovate and hairy exterior scales of the involucre ; the inner 

 enclosing the achenia, tuberculate-scabrous towards the base, dilated above 

 into a short smooth hood, truncate at the summit, with the margin entire and 

 involute. 



Texas, Dr. Ridddl ! — Plant 6-10 inches high. Leaves 1-2 inches long, 

 somewhat canescent, above witli hispid, beneath with weak hairs. Rays 

 about half an inch long. Chaff" of the receptacle laciniate-fimbriate at the 

 summit. — Nearly allied to (and possibly not distinct from) M. cinereum, 

 DC, a Mexican species collected by Berlandier, which is also remarkable 

 fur having white rays. 



Div. 2. MiLLERiE^, DC — Fertile and sterile flowers in the same 

 heads ; the former few, ligulate, or sometimes tubular and 3-cleft ; the latter 

 central, tubular. Achenia not corticate, (that is not coherent with the scales 



* We have used the term as employed and defined by De CandoUe in this place. 

 But in the Heliopsidece, and other pkices, this author also terms those achenia cor- 

 ticate in which the exterior covering (calyx-tube) is separable from the interior. 



