ON SOUTH-AMERICAN APOCYNACEA, 
MACOUBEA. 
This genus of Aublet, established upon a tall tree in Guiana, has been placed by most 
botanists in Clusiacee, though Cambassédes expressed a contrary opinion. Its floral 
structure is unknown; but in its other characters it appears to belong to the Apocynacee, 
because all parts of the plant yield a lactescent juice: its leaves are opposite, with 
straight divergent nerves arcuately conjoined near the margin, and upon petioles some- 
what embracing the branch. The fruit, supported upon a short pedicel, is drupaceous, 
globular, as large as an orange, much resembles that of Cupirana, borne upon the per- 
sistent calyx; it is indehiscent, with a rough, brown, thick pericarp, apparently unilo- 
cular, but only by abortion, as Jussieu observed, for the dissepiment of the ovary is 
here thrust on one side: it contains several oblong curving seeds, with a hilum in the 
middle of a ventral furrow ; they are covered by a pulpy covering, which when dry is thick 
and spongy; each contains, within albumen, an embryo with two fleshy cotyledons and a 
small radicle. These characters show a close approach to Ambellania; and Aublet must 
have been aware of this affinity, as he figures the two genera in juxtaposition. Only one 
species is known, and that imperfectly. The following character is partly formed 
after the examination of Aublet’s typical plant, now in the herbarium of the British 
Museum. 
1. Macovsea GuraxENsIS, Aubl. Pl. Guian. ii. suppl. p. 18, tab. 378 ; Juss. Gen. p. 257; Juss. Ann. 
Mus. xx. p. 466; Cambass. Mém. Mus. xvi. p. 396; DC. Prodr. i. 364; Benth. & Hook. Gen. i. 
169: arbor lactescens, foliis oppositis, ellipticis, utrinque subacutis, integris, glaberrimis, supra glauco- 
viridibus, nervis paullo divergentibus arcuatim nexis, reticulatis; petiolis semiteretibus, in nodum 
transversim fere junctis, limbo 8plo brevioribus: racemis oppositis, terminalibus, petiolo fere duplo 
longioribus, crebre plurifloris, floribus brevissime pedicellatis ; sepalis minoribus, rotundatis, convexis, 
imo gibbosis, et in cupulam brevem coalitis, carnosis, valde imbricatis: pedunculo fructifero brevi ; 
drupa majuscula, subsphzrica subcompressa, vel obsolete trisuleata, punctis griseis notata, abortu 
1-loculari ; seminibus plurimis, obtuse oblongis, ad raphen longitudinaliter sulcatis, in carne fungosa 
nidulantibus; embryone intra albumen, oblongo, cotyledonibus 2, plano-convexis, radicula minima 
nexis, In Guiana: v. pl. s. in herb. Mus. Brit. Cayenne, in sylvis (Aublet) ; fruct. non vidi. 
A tree 40 feet high, with a trunk 18 in. in diameter ; its hard wood, of a greenish yellow 
eolour, emits a fetid odour, all parts of the plant yielding a lactescent juice. The nodes 
of its branches are 1-2 in. apart; the leaves are 4 in. long, 2 in. broad, on petioles 4 in. long, 
conjoined across the node. The fruit is suspended by a pedicel 2 lines long, is about 
3 in. in diameter, the pericarp being hard and 1 line thick; the seeds are $ in. long, 
l in. broad, slightly curved and suleated along one side, by the middle of which they 
seem to be attached. c2 
