20 ON SOUTH-AMERICAN APOCYNACEZ. 
''HEVETIA. 
A new species, from Venezuela, is here added to this genus, which nearly approaches 
the handsome plant described and figured by Mr. Bentham in the Botany of the 
‘Sulphur,’ p. 124, tab. 43. I will first, however, explain my view of the carpological 
strueture of the genus, which is not quite exactly described by Prof. DeCandolle in his 
* Prodromus;' and it is difficult to understand the long description of Dr. Müller in 
Mart. * Fl. Bras., which is not correct. 
My analysis was made from a plant of T. ahouai, cultivated in Rio de J anejro. This 
species is well figured in Lamarck's * Illustr.’ tab. 170: the compressed globular ovary is 
pseudo-4-locular, the true dissepiment being across the shorter diameter, having on each 
side a very broad placentary expansion extending nearly to the wall of the cells in the 
direction of the longer diameter, thus appearing pseudo-4-celled, a single ovule being 
peltately attached upon each side of each branch of the placenta. This structure is 
maintained in the ripe fruit; within the pericarp is a heart-shaped compressed osseous 
nut, shown in a reversed position in Lamarck's plate: along the emarginated apex of this 
nut is a suture, which extends nearly to the base along each edge, into which a knife 
easily penetrates ; but it requires some force to cut through its more solid base: we thus 
divide the nut into two plano-convex portions, the division being through the bilamellar 
placente: upon the surfaces of the division, on each face a cord of spiral vessels rises 
from the base, diverges upwards, and is lost at a spot opposite to each seed, and therefore 
opposite to the hilum of each: around this spot, within the cell, is a deep hollow in 
the placenta, formed by the pressure of the rounded peltate hilum: the 4 seeds, which 
fill the spaces of the A pseudo-cells, are irregularly globose, flattened on one side around 
the large convex hilum: the testa is stoutly chartaceous, of a brownish colour, and so 
firmly attached to the hilum, that it cannot be there detached without rupture; this 
integument is lined within by a network of snow-white branching threads of the raphe; 
the inner integument is free, membranaceous, and of a darkish colour, closely investing 
an embryo, without any trace of albumen, which consists of 2 roundish plano-convex 
fleshy cotyledons united by a short obtusely conical radicle, projecting horizontally and 
centrifugally to the outer edge of the cell: this embryo is therefore heterotropous ; 
i. e. the hilum is laterally placed between the two extremities of the embryo. The new 
species before mentioned is defined in the following manner :— 
THEVETIA CALOPHYLLA, nob.: ramulis teretibus brunnco-opacis: foliis alternis, lanceolato-oblongis, imo 
cuneatis, apice acute acuminatis, chartaccis, marginibus subrevolutis, supra viridibus, opacis, corru- 
gulatis, ad nervos semiimmersos sulcatulis, subtus opacis, brunnescentibus, corrugulatis, nervis ` 
omnino immersis ; petiolo semitereti, limbo 11-12plo breviore : racemo brevi, terminali, paucifloro; . 1 
pedicellis subvalidis, calyce 3plo longioribus; sepalis oblongis, acutis, membranaceis, parallele. dE 
nervosis; corolle tubo cylindrico, supra medium ampliore, limbi segmentis 5, tubo dimidio brevi- 
oribus, dolabriformibus, dextrorsum contortis, cum appendicibus 5 subacutis intra faucem alternis; 
staminibus 5, sub squamas insitis, inclusis, ex annulo piloso ortis; filamentis brevibus; antheris 
sine eonnectivo profunde 2-lobis, lobis imo divaricatis; disco annulari, carnoso; ovario paullo 
longiore, glabro, 2-loculari ; stylo longo, filiformi, apice in clavunculam cylindricam 10-sulcatam imo 
