DISTRIBUTION OF TRIBES. 433 
claims to consanguinity sufficient to be thus associated, and may 
possibly be, like Lagascea, isolated remnants of old, almost extin- 
guished races or local divergent forms, whose connexions have not 
been properly appreciated. In the mean time they are somewhat 
technieally associated by their mostly Helianthoid habit, foliage, 
and involucres, by their usually small capitula with a few female 
fertile florets ; the disk-florets always sterile with undivided styles ; 
the achenes of the fertile florets Helianthoid, rather large, often 
dorsally flattened or thick, subtended by or enclosed in the inner 
involucral bracts (or outer receptacular palez), without any or with 
a short coroniform or Helianthoid pappus; the abortive disk-achenes 
without any pappus, their florets crowded in the centre of the 
capitulum without intervening pales, or, at most, with a few 
reduced subtending sete. Geographically they are somewhat 
scattered ; the majority are American and tropical Heptanthus, 
three species, Pinillosia, three species, and the monotypic Lanta- 
nopsis, are restricted to Cuba; Tetranthus, two species, is also 
insular, restricted to San Domingo ; Elvira has three species, which 
some may regard as so many distinct monotypic genera, of which 
two are insular, limited to the Galapagos, the third dispersed from 
Central over many parts of tropical South America, as is also the 
monotypic Milleria ; Stachycephalum, also monotypic, is limited 
to Mexico,—the above seven (or nine) genera having, perhaps, 
sufficient characters in common to be united into one genus of a 
higher grade; all have opposite or radical leaves and few-flowered 
small capitula. Technically allied to them, with small few-flowered 
capitula and radical or alternate leaves, and, perhaps, really of 
very distant affinities, is a genus of a much wider geographical 
distribution. Adenocaulon, with five species, belongs to the tem- 
perate or mountain W.-American region, two species being Chilian, 
one N.W.-American, and two, possibly varieties of the N.- Ame- 
rican one, inhabitants respectively of Japan and the Himalaya. 
This genus had hitherto been classed with Tussilago, where, 
to my mind, it would be a more perfect stranger than amongst 
Milleriez. 
The three remaining genera, Riencourtia, five or six species, 
from eastern tropical South America, Desmanthodium, two Mexican 
species, and Clibadiym, with fourteen species more generally dis- 
persed over tropical and subtropical America, establish the connect- 
ing link between Milleriew and Melampodinezx and the still more 
normal Helianthoid subtribe Verbesinez. 
212 
