Swartzia rediviva R.S.Cowan

Description

Authors: Benjamin M. Torke and Vidal de Freitas Mansano

Type: Suriname, [Sipaliwini]: in montibus Bakhuis inter flum. Kabalebo et Coppename Sinistrum: banks of Linker Coppename River, to 3 km downstream of base camp, 3 Feb 1965 (fl), P. A. Florschütz & P. J. M. Maas 2738 (Holotype: U-193207; Isotypes: NY, US).

Description: Tree to 15 m+; trunk to ca. 30 cm; pubescence of appressed, fairly straight whitish or golden hairs, these mostly less than 0.2 mm long; leaf-bearing branchlets ca. 1.5–3 mm thick at middle of internodes, sparsely strigulose, glabrescent. Leaves imparipinnate, with 1–2 pairs of opposite to subopposite lateral leaflets; stipules ca. 1.5 x 0.5 mm, triangular, glabrescent, caducous; petiole 1–2.7 cm long, unwinged, sparsely strigulose, glabrescent, the pulvinus 3–5.6 mm long; rachis 3–8 cm long, longitudinally bicarinate adaxially, sparsely minute-strigulose, glabrescent; stipels 0.4–0.8 mm long, triangular; petiolules 3–5 mm long, sparsely strigulose, glabrescent; laminas 1.5–3.2 x longer than wide, 7–17 x 2.5–7 cm, stiffly subcoriaceous, elliptic or obovate, somewhat decurved at margin, discolorous, acute or obtuse at base, briefly acuminate at apex, the acumen rounded, ca. 3–6 mm long, the adaxial surface lustrous, mostly glabrous, sparingly strigulose along midrib near base, the abaxial surface sparingly minute-strigulose, glabrescent, the venation salient on both surfaces, the midrib raised-cariniform on both surfaces, the secondary veins ca. 12, initially ascending at 20–37°, forming loose submarginal loops, higher-order venation reticulate. Inflorescences simple racemes, borne from leaf axils or from defoliate nodes of annotinous or somewhat older branches; axes 6.5–18.5 cm long, 2.3–3.1 mm thick near base, irregularly angular in cross section, thinly to somewhat densely strigulose; bracts ca. 1.5 x 1–1.2 mm, triangular or ovate, glabrous adaxially, thinly strigulose abaxially, caducous; pedicels 9.5–11.4 mm long, 1.9–2.2 mm thick at middle, dorso-ventrally compressed, dilated apically, thinly to somewhat densely strigulose, glabrescent toward apex; bracteoles 1.2–1.3 x 0.4–0.5 mm, opposite to subopposite, inserted in the distal third of pedicel, narrowly triangular to ovate-lanceolate, glabrous adaxially, thinly strigulose abaxially; flower buds 11.2–13.5 x 7.9–9.2 mm, ellipsoid, longitudinally costate, entirely glabrous or with a few trichomes at extreme base. Calyx segments 3–4 in number, 3.7–6.8 mm wide, strongly recurved, entirely glabrous or with a few trichomes at extreme base abaxially. Corolla monopetalous; petal light yellow, the claw 4.3–4.4 mm long, 1.1–1.3 mm wide at middle, the limb broadly ovate-deltoid, 18.5–22.8 x 18.9–24.2 mm, glabrous. Androecium glabrous, more or less zygomorphic, the stamens of two sizes; larger stamens 7–8, abaxial, the filaments ca. 20 mm long, 0.6–0.8 mm thick near base, basally dilated, dorso-ventrally compressed, the anthers 1.3–1.6 x 0.9–1 mm, elliptic or oblong-elliptic in outline, invaginated between thecae, the connective not prolonged at apex; smaller stamens ca. 200, the filaments 6.5–16.1 x ca 0.1 mm, the anthers 0.7–1.2 x 0.5–0.9 mm, elliptic to oblong-elliptic in outline, invaginated between thecae, the connective not prolonged at apex. Gynoecium monopistillate, glabrous; stipe ca. 15–17 x 0.8 mm, more or less terete; ovary ca. 7–8 x 2.2–2.5 mm, oblong-lunate, laterally compressed, the locule glabrous; ovlues 9–10; style ca. 4.5 mm long, ca. 0.6 mm thick at middle, obliquely terminal, recurved; stigma capitellate. Fruits unknown.

Common names: No common names have been recorded.

Geographic distribution: Swartzia rediviva is known only from the remote type locality along the upper Coppername River in west-central Suriname.

Ecology: The species was found growing on the riverbank.

Phenology: The collection, a flowering specimen, was gathered in February.

Taxonomic notes: Although he considered S. rediviva to be a taxonomically isolated species, Cowan (1973) speculated about a possible relationship with S. parviflora, a species later placed in section Orthostylae by Torke & Mansano (2009). However, the combination of a yellow petal, gynoecium with the stipe much longer than the ovary, and consistently bracteolate pedicels, fits better with Torke and Mansano’s (2009) placement of S. rediviva in section Recurvae. Although it has not yet been included in phylogenetic studies, S. rediviva may be most closely related to S. hostmannii, another species endemic to the interior Guianese forest; both have relatively large flower parts, glabrous flower buds, and a more elongate style than is typically for the section. But the latter is immediately separable from S. rediviva by its unifoliolate leaves and sericeous ovary.

Uses: No uses have been recorded.

Etymology: The epithet, meaning “revived,” was given by Richard S. Cowan “in allusion to the state of the author’s mind, rather than to a characteristic of the plant described.” the author in 1973 when the plant was described having returned to his research activities after a decade of administrative duties.

Conservation status: Data are insufficient to assess the conservation status of the species. Known from a single collection from the remote interior of Suriname, S. rediviva has not been re-collected since its discovery in 1965, despite subsequent expeditions in the region. It is likely rare, geographically restricted, or both. However, the type locality lies within a large region of intact and poorly explored wilderness. Implementation of the West Suriname Development Plan, should it come to pass, might threaten the species’ habitat in the future.

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