ROBINSON. —— STUDIES IN THE EUPATORIBAE. 33 
Alomia dubia, n. sp., herbacea erecta perennis sordide pubescens 
4-7 dm. alta; radice lignescenti ramosa; caulibus 1 vel pluribus 
teretibus striatulis foliosissimis ad inflorescentiam corymbosam simpli- 
cissimis ; foliis alternis oblanceolatis obtusiusculis crenato-serratis 2-3 
cm. longis 4-10 mm. latis basi attenuatis subpetiolatis utrinque dense 
et sordide pubescentibus supra rugulosis subtus reticulatis ; corymbis 
laxe ramosis 7-15 cm. latis supra modice planis, ramis ascendentibus 
saepius 3-5-capituliferis, bracteis linearibus 5-15 mm. longis; eapitulis 
ca. 65-floris ca. 1 em. diametro 8-10 mm. altis; involucri campanulati 
Squamis subbiserialibus lanceolato-linearibus subaequalibus dorso pu- 
berulis nervosis apice attenuatis tomentellis; corollis roseis 4 mm. 
longis, tubo proprio gracili externe glanduloso-hirsutulo basi plus 
minusve expanso supra in fauces turbinato-campanulatos gradatim 
ampliato, limbo purpurascenti-tomentello ; achaeniis nigris 5-angulatis 
glaberrimis basi mediocriter angustatis apice rotundatis ab annulo 
albido cartilagineo coronatis omnino calvis. — Brazil, presumably from 
the Prov. Goyaz, Dr. A. Glaziou, n. 21579 (hb. Kew.). 
Although there can be no doubt that this species is technically an 
Alomia and must be referred to that genus, as the genera of this affinity 
are now divided, it must be confessed that Alomia looks suspiciously 
like an artificial aggregate of species which may well have had a very 
different origin. Its species are varied in habit, and approach on the 
one hand so close to Ageratum, and on the other to T'richogonia, that 
it may well be doubted whether they are not, at least in some cases, 
“formae epapposae” of these genera. The present species closely 
resembles in habit and many of its features Trichogonia. It should 
be noted that forms of at least two species of Trichogonia have been 
found in which part or all the achenes were entirely destitute of 
pappus. The species here described, however, is clearly distinct from 
any hitherto characterized species of either genus. T'richogonia with 
its plumose setiform pappus is certainly very distinct from Ageratum 
with a pappus of few distinct or somewhat connate scales, yet the 
Alomiae, which are entirely destitute of pappus or have only an 
annular rudiment in its place, show such transitions of habit, involucre, 
pubescence, ete., that they neither carry conviction as a distinct genus, 
nor are they capable of satisfactory grouping as pappusless forms of 
the pappus-bearing genera. The genus Alomia is as yet very poorly 
represented in herbaria, and until further materi been collected, 
it seems impracticable to revise the generic limits of the three genera 
here concerned. 
HantwriGHtta FLORIDANA Gray, Proc. Am. Acad. xxiii. 265 (1888). 
izing this monotypic genus from Florida, Dr. Gray un- 
In 
VOL. xLit.——-§8 
