WESTERN TROPICAL AMERICA. lll 
Herba ut videtur annua, pedalis vel altior, ramis alternis elongatis gracilibus teretibus nune puberulis nune 
molliter villosis. Folia inferiora 1}-2-pollicaria, longiuscule petiolata, obtusiuscula, utrinque pube minuta 
mollia, minute pellucido-punctata ; superiora minora, angustiora. Capitula ad apices ramulorum ultimorum 
2-3, breviter pedicellata, 23 lin. longa, forma fere Spilanthis. Involucrum turbinatum, squamis subbiserialibus 
paucis pallide virescentibus, pube molli subviscosa. Receptaculum elongato-conicum. Palea concave, corollis 
vix breviores, apice ciliates, exteriores squamis involucri subsimiles, interiores lineari-spathulate, hyaline. 
Corollee tubus tenuis, basi dilatatus et deorsum pilosus ; faux elongata, tubo duplo amplior, glabra ; dentes limbi 
breves, patentes. Antherse incluse, apice ovato-appendiculate. Styli rami obtusiusculi, exserti, hispiduli. 
Achenia tetragona, nigra, glabra, omnino calva, 
The genus JIsocarpha, to which this plant belongs, is rather that established 
by Lessing, in the Linnea, v. 5. p. 141, than the original Isocarpha of Brown, 
founded on the I. oppositifolia. It is true that Lessing afterwards considered his 
as the same as Brown’s, and as differing from Calydermos by the style, that of 
Eupatoriacee, and that De Candolle, following him in this opinion, has placed 
Isocarpha of Brown among Eupatoriacee, but has copied Brown’s description of 
the style, altering only the phraseology to suit the general views adopted by him: 
“Styli rami elongati, extus convexi, hispiduli, acuti,” a character accurately taken 
from J. oppositifolia, Br., but not applicable to the J. echioides, Less., where the 
branches of the style are described and figured as obtuse, nor yet conformable to 
the general form of the style in Eupatoriacee. It is probable that, on a further 
investigation, the present species, with three or four unpublished Brazilian ones, 
and the I. echioides, Less. (with which I am unacquainted), will be found to be true 
Eupatoriacee, whilst the I. oppositifolia, Br., appears to be strictly congener with 
the Dunantlia achyranthes, DC., admirably figured in the 4th vol. of Delessert's 
Icones, and to be nearly allied to Spilanthes. With regard to the names to be 
respectively adopted for the two genera, it would occasion less confusion were 
Lessing’s to retain that of Isocarpha, and were the J. oppositifolia to be transferred 
to Dunantia; but this would perhaps be too contrary to the rules of priority to be 
adopted. I refrain, however, for the present from establishing any further the 
separation, as I have no opportunity of examining three of the four species 
enumerated in the Prodromus. 
Plate XLI. fig. 1, head of flowers, vertical section ; fig. 2, scale of the receptacle ; fig. 3, flower ; 
fig. 4, upper part of the style; fig. 5, achenium ; fig. 6, the same cut across : all magnified. 
403. Ca.zstina corymbosa, DC. Prod. v. 5. p. 108.—San Blas and Tepie.—A ie appa- 
rently well distinguished from C. ageratoides, with which some botanists unite it. 
404. Catnstina petiolata, Hook. et Arn. Bot. Beech. p. 433. (sp. n.)—Realejo. 
405. Acrratum conysoides, Linn.—DC. Prod. v. 5. p. 108.—Columbia. 
406. Apencsremma Swartzi, Less--DC. Prod. v. 5. p. 110,-—Bolia, saleepte spe som 
pedalia, 4-5-poll. lata—Salango. a 
