Swartzia aptera DC.

  • Authority

    Cowan, Richard S. 1967. Swartzia (Leguminosae, Caesalpinioideae Swartzieae). Fl. Neotrop. Monogr. 1: 3-228. (Published by NYBG Press)

  • Family

    Fabaceae

  • Scientific Name

    Swartzia aptera DC.

  • Type

    Type collection. J. Martin s.n. (holotype G; isotypes BM, C, Fl, LE, P, R, US), Cayenne, French Guiana.

  • Synonyms

    Tounatea aptera (DC.) Taub., Tunatea aptera (DC.) Kuntze

  • Description

    Description - Shrub to small tree 3-10 m tall, the branchlets glabrous, slender; stipules caducous to deciduous, ca 1 mm long, linear, glabrous; leaves glabrous, the petioles (9-) 14-22 mm long, terete, slender, the rachis (7-) 15-28 mm long, terete, exalate, estipellate, slender; leaflets unijugate, the petiolules (2-)3-4.5 mm long, canaliculate, the blades (3.8-)5-7(-10) cm long, (1.7-)2-4.5 cm wide (the terminal leaflet usually longer), oval or elliptic or ovate, the base of the lateral leaflets rounded-obtuse to acute, that of the terminal one subobtuse to cuneate, the apex of all the leaflets caudate-acuminate, the tip 10-20 mm long, linear and finally slightly retuse or truncate-obtuse, the upper surface usually drying green and the lower tan-brown, the venation obscure, the costa impressed above, salient beneath, the primary veins plane; inflorescences axillary, 2- or 3-flowered or occasionally the flowers solitary, 5-6.5 cm long, the axis glabrous or sparsely strigulose minutely, the primary bracts caducous, 0.7-1 mm long, linear, uncinate, densely strigulose, the secondary bracts deciduous, 0.7-1 mm long, linear, glabrous or sparsely strigulose minutely, the bracteoles arising in the upper half of the pedicels, ca 0.7 mm long, persistent, linear; flowers glabrous, the pedicels 23-42 mm long; buds globose, 6-9 mm diameter; calyx segments 4 or 5, deciduous; petal orange-colored, glabrous, the claw 4-6 mm long, the blade 14-22 mm long, 15-17.5 mm wide, rounded to oblate, the base rounded or truncate; stamens glabrous, the 12-16 larger ones with filaments 17-28 mm long and oval anthers 0.9-1 mm long, 0.8-0.9 mm wide, the pollen elliptic, 34-36.5 µ long, 26 µ diameter, the smaller stamens with filaments ca 15 mm long, the oval anthers 0.9 mm long, 0.7-0.8 mm wide, the pollen globose, 26-28.5 µ diameter; gynoecium glabrous, the stigma obtuse, the style ca 4 mm long, the ovary about 4-ovulate, arcuate-fusiform, 6-8 mm long, 1-1.5 mm wide, the gynophore 15.5-19 mm long; fruit 4-7 cm long (plus the persistent style ca 4 mm long), ca 2 cm wide, elliptic in outline, the stipe 22-26 mm long.

  • Discussion

    The binomial for this species is generally considered to have been published in De Candolle’s memoir on the Leguminosae, but the part of that work containing his observations on Swartzia was not published until 1826. By that date the Prodromus had appeared and constitutes an earlier publication date for S. aptera (cf. Stafleu & Stearn, Taxon 9: 169-171. 1960).

    The bracteoles at the base of the pedicels and the axillary few-flowered inflorescences clearly place this species in sect. Possira, rather than showing any near relationship to S. recurva which was assigned by Ducke to varietal status within S. aptera. The inflorescence of this species, however, is rather anomalous and requires further consideration. Here the bracts, like those of the other species of sect. Possira, are obviously relictual foliar organs and at the base of the pedicels there are two organs, which are termed bracteoles elsewhere in the section; in this species I have called them secondary bracts. In addition, there is still another pair of structures on the pedicels, exactly homologous with what are called bracteoles in sect. Swartzia. Such an intermediate condition, I believe, supports the view that these groups are better considered sections rather than subgenera.

    The nearest relative of S. aptera is probably S. longistipitata which has more pairs of leaflets per leaf, ebracteolate pedicels, and calyx segments which are densely pubescent on the inner surface.

  • Common Names

    Panacoco

  • Distribution

    (Fig. 39). Apparently restricted to the region of the Oiapock River, which forms the boundary between French Guiana and northeastern Brazil. Most of the collections were made in the riverine forest on islands in or alongside rapids or waterfalls on soils overlying the granite basement rock. FRENCH GUIANA, “bords du riviere de la Comte, de Gene, 40 lieues de Cayenne,” Martin 57 (Fl).

    French Guiana South America| Brazil South America| Amapá Brazil South America|