CONTRIBUTIONS TO BOTANY. 
63 
and in its free 2-locular ovary, seated within a fleshy disk. It 
difiers from BignoniacecB in the species being for the most part 
herbaceous, with alternate or radical leaves, which are never 
strictly pinnate ; in its prominent bifurcate placentations, which 
frequently produce the appearance of four cells in the fruit ; in 
its very numerous minute and always pendent seeds, and its 
terete radicle with very small cotyledons. These characters are 
sufficient to establish its claim to a distinct ordinal rank. The 
ovary in CyrtandracecR appears to be composed of two carpellary 
leaves, placentiferous on their midribs and conjoined by their 
sterile margins, as in Jacaranda and Crescentia-, it is conse- 
quently unilocular, with two opposite parietal pla- Fig. 17. 
centae, which severally bifurcate (fig. 17). By the sub- 
sequent growth and approximation of the placentae, the 
2-vaJved capsular fruit frequently becomes spuriously 
2-locular or falsely 4-celled : the generally comose extremities 
of the seeds bear some analogy to a somewhat similar develop- 
ment in Sparattosperma and Astianthus among Bignoniacece. 
The PedaliacecB (excluding Sesamea for reasons to be presently 
stated) con’espond in the constitution of their carpels with the 
Crescentiacea, and therefore, in some degree, with the Eccremo- 
carpecE. The ovary generally consists of two carpels, placenti- 
ferous on their midribs and conjoined by their sterile margins ; 
it is therefore 1 -locular, with two opposite parietal 
prominent placentae formed of two very recurved la- 
mellar plates, which bear the ovules on their margins 
(fig. 18) : hence the fruit, by the growth and subse- 
quent hardening of the placentae, becomes pseudo-4-locular. The 
figure of the ovary and fruit of Martynia annua given by Gaertner 
(de Fruct. tab. 110) afibrds a very correct idea of this structure, 
as I had an opportunity of verifying by an examination of the 
fruit, during its several stages of growth, when on my journey 
across the Pampas. Taking this example as an exponent of the 
general structure of this group, it appears to establish its right 
to a distinct ordinal rank among the Bignonial alliance. 
The SesamecB, in the structure of their carpels, differ from all 
the before-mentioned groups, and should therefore be excluded 
from the Bignonial alliance. Their ovary consists normally of 
four carpellary leaves, placentiferous (not on their midribs, but) 
upon their margins, which, are inflected and meet in one com- 
mon axis, where they form a central column sur- 
rounded by four cells which lie in parallel pairs 
(fig. 19) ; thus conjoined, the capsular fruit be- 
comes 4-celled and 2-valved, the seeds remaining 
attached to the central column, which separates from the valves. 
DeCandolle (Prodr. ix. 253) arranged the Pedalinece as a tribe of 
Fig. 19. 
Fig. 18. 
