lected at Sierra Leone by Professor Afzelius, that two plants having this form of spike are known in that colony j and two species, with similar inflorescence, probably distinct from those of Africa, are described in the manuscript Flora Indica of Dr. Roxburgh. All these plants possess characters fully sufficient to distinguish them from Inga, to which they have hitherto been referred. The new genus which they form, one of the most striking and beautiful in equinoxial Africa, I have named P a r k ia *, as a tribute of respect to the memory of the celebrated traveller, by whom the fruit of this genus was observed in his first journey, and who, among other services rendered to botany, ascertained that the plant producing Gum Kino is a species of Pterocarpus f. I have formerly endeavoured to distinguish Mimoseae from Caesalpinese, by the valvular aestivation of both its floral envelopes, and by the hypogynous insertion of its stamina. Instances of perigynous insertion of stamina have since been noticed by MM. Kunth and Auguste de St. Hilaire ; but no exception has been yet pointed out to the valvular aestivation of their calyx and corolla. * PARKIA. Ord . N a t. Leguminosee-Mimoseee: Ceesalpineis proximum genus. C h a r. Gen. Calyx tubulosus ore bilabiato (4 ); restivatione imbricata! Petala 5. sub- equalia, supremo (paulo) latiore; «stivatione conniventi-imbricata. Stamina deoem, hypogyna, monadelpha. Legumen polyspermum : epicarpio bivalvi; endocarpio in loculos monospermos sarcocarpio farinaceo tectos solubili. Arbores (Afrtcana et In d ia orientalis) inermes. Folia bipinnata, pinnis foliolisque multijugis; etipulis minutis. Spicce axillares, pedunculatce, clavatce J'loribus inferioribus (dimidii cylindracei racheos) scepe masculis. P a r k i a Africana, pinnis sub-20-jugis, pinnulis sub-30-jugis obtusis intervalla tequantibus, eicatricibus distinctis parallelis, glandula ad basin petioli, rachi communi eglandulosa, partiolium jugis (2-3) summis glandula umbilicata. Inga biglobosa, Palis de Beauv. Flore d'Oware, 2. p. 53. tab. 90. Sabine in Hortic. Soc. Transact. 5. p. 444. De Cand. Prodr. 2. p. 442. Inga Senegalensis. De Cand. Prodr. 2. p. 442. Mimosa taxifblia. Per s. Syn. 2. p. 266. n. 110. Nitta. Park's First Journey, p. 336—337. t Park's Second Journey, p. cxxiv. where it is stated to be an undescribed species of that genus. Soon after that Narrative appeared, on comparing Mr. Park's specimen, which is in fruit only, with the figure published by Lamarck in his Illustrations (tab. 602. f . 4.), and with M. Poiret’s description (Encyc. Meth. Hot an 5. p. 728.), I referred it to that author’s P. erinacca, a name which is, I believe, adopted in the last edition of the Pharmacopoeia of the London College. Dr. Hooker has since published fi drawing of the same plant by the late Mr. Kummer, and considering it a new species, has called it Pterocarpus Senegalensis. (Gray's Trav. in Western Africa, p. 395, tab. D.) Parkia, however, differs from other Mimoseae not only in its aestivation, which is imbricate, but in the very manifest irregularity of its calyx, and in the inequality of its petals, which, though less obvious, is still observable. Erythraphleum, another genus indigenous to equinoxial Africa, which I have elsewhere* had occasion to notice, and then referred to Caesalpineae, more properly belongs to Mimoseae, although its stamina are perigynous. In this genus, both calyx and corolla are perfectly regular, and their aestivation, if not strictly valvular, is at least not manifestly imbricate, though the flower-buds are neither acute nor angular. In Erythrophleum and Parkia, therefore, exceptions to all the assumed characters of Mimoseae are found, and there is some approach in both genera to the habit of Ctesalpineae. It is still possible, however, to distinguish, and it will certainly be expedient to preserve, these two tribes or orders. Abandoning divisions strictly natural, and so extensive as the tribes in question, merelybecausewe may not be able to define them with precision, while it would imply, what is far from being the case, that our analysis of their structure is complete, would, at the same time, be fatal to many natural families of plants at present admitted, and among others to the universally received class to which these tribes belong. No clear character, at least, is pointed out in the late elaborate work of M. De Candollef, by which Leguminosse may be distinguished from Terebintaceae and Rosaceae, the orders supposed to be the most nearly related to it. It is possible, however, that such characters, though hitherto overlooked, may really exist; and I shall endeavour to show that Leguminosse, independent of the important but minute differences in the original structure and developement of its ovulum, may still be distinguished at least from Rosacese. In the character of Polygale®, which I published in 18141, I marked the relation of the parts of the floral envelopes to the axis of the spike, or to the subtending bractea. I introduced this circumstance chiefly to contrast Polygaleie with Leguminosse, and to prove, as I conceived, that Securidaca, which had generally been referred to the latter family, really belonged to the former. M. de Jussieu, who soon after published a character of Polygale®, entirely omitted this consideration, and continued to refer Securidaca to Leguminosse. M. De Candolle, however, in the first volume of his Prodromus, has adopted * Tuckey’s Congo, p. 430. t Memoires sur la Famille dcs Lcgumincuscs. J Flinders’s Voy. to Terra Austr. 2. p. 542. hh*
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