MELIACE^. 



^ILVA OF NORTH AMElilCA, 



99 



SWIETENIA. 



Flowers perfect ; calyx 5-lobed, the lobes contorted in aestivation ; petals 5, con- 

 Yolute in aestivation ; filaments united into an urn-shaped tube. Fruit, a 5-celled 

 capsule. Leaves alternate, abruptly pinnate. 



Swietenia, Jacquin, Stirp. Am. 127. — Linnseus, Ge^i. ed. Mahagoni, Adanson, Fam. PI. ii. 343 (excl. syn. Guidonia, 

 6,209. — A. L. de Jussieu, Gen. 266. — Meisner, Gen. Plumier). 



47. — Endlicher, Gen. i. 1053. — Bentham & Hooker, 

 Gen. i. 338. — Baillon, Hist. PL v. 504. 



Noble trees, ^Ath. heavy dark red wood. Leaves glabrous, destitute of stipules, long - petioled ; 

 leaflets opposite, petiolulate, usually obUc^ue at the base. Flowers small, in axillary or subterminal pani- 

 cles produced near the ends of the branches. Pedicels slender, bibracteolato near the middle. Calyx 

 minute, much shorter than the spreading petals. Staminal tube connate with the petals, ten-lobed, the 

 lobes convolute in eestivation ; anthers ten, fixed by the back below the sinuses of the staminal tube, 

 included, introrse, two-celled, the cells opening longitudinally. Ovary free, sessile on the annular disk, 

 ovoid, five-celled, the cells opposite the petals ; style erect, exserted from the tube of stamens, dilated 

 into a discoid five-rayed stigma. Ovules many In each cell, suspended from the central axis, seml-anat- 

 ropous ; raphe ventral ; micropyle superior. Capsule five-valved, septicidally dehiscent from the base, 

 the valves bllamellate, separating from a persistent five-angled axis thickened towards the apex and 

 five-winged towards the base. Seeds suspended from near the summit of the axis. Imbricate In two 

 ranks, compressed, eraarglnate, produced above into a long membranaceous whig with the hilum in Its 

 apex and transversed by the raphe ; chalaza lateral. Embryo transverse ; cotyledons conferrumlnate 

 with each other and with the thin fleshy albumen ; radicle short, papillseform, opposite the chalaza. 



Swietenia, of which three species are recognized. Is tropical American and west-tropical African. 

 Swietenia Mahagoni, the type of the genus and one of the most valuable timber trees known, Is distrib- 

 uted from south Florida, the most northern station of the genus, to Mexico, Central America, and Peru. 

 Swietenia humilis,'- perhaps a form of the last species. Is found on the Pacific coast of Mexico. Swie- 

 tenia Angolensis,^ a large deciduous tree, inhabits the mountain forests of central Quitta in west- 

 tropical Africa.^ 



The genus was named by Jacquin in honor of Baron von Swieten, a distinguished physician of the 



eighteenth century.* 



1 Zucearlni, PI. Hort. et Herb. Monac. ii. 355, t. 7 (Munchner 

 Denkschriff). — C. de CandoUe, Monogr. Phaner. i. 723. — Hemsley, 



Bot. Biol. Am. Cent. i. 183. 



2 Welwitsch, "Apont. Ann. do Conselh. 561."-C. de Candolle, 



Monogr. Phaner. i. 724. 



3 A fourth species, Swietenia macrophylla, King (Hooker Icon. 

 xvi. t. 1550), is described. It was raised several years ago in the 

 Calcutta Botanic Garden from seeds said to have been sent from 

 Central America. The leaflets and the fruit are much larger than 



those of ordinary forms of Swietenia Mahagonij from which, how- 

 ever, it does not appear to differ in any other respect. 



* Gerard von Swieten (1700-1772) ; a native of Leydcn, where 

 he became a professor of medicine in the University, and a disciple 

 of Boerhaavc, Being a Roman Catholic, Swieten was obliged to 

 resign his professorship In the Protestant University of Leyden ; 

 but Maria Theresa invited him to Vienna, whore he reformed the 

 study of medicine in the University, induced the empress to estab- 

 lish the Botanic Garden, and laid the foundation for the celebrated 

 medical school. 



