Sloanea subsessilis D.Sampaio & V.C.Souza, 2011

Sampaio, Daniela & Souza, Vinicius C., 2011, Three new species of Sloanea (Elaeocarpaceae), Phytotaxa 16, pp. 45-51 : 47-49

Sloanea subsessilis D.Sampaio & V.C.Souza , sp. nov. ( Fig. 2 )

Affinis Sloanea floribunda sed ovario sessili, folio subsessili et stylo apice 4-partitus differt.

Type: — BRAZIL. Mato Grosso: Barra do Bugres, Fazenda Ochsenfeld, mata de galeria, 23 October 1995, Hatschbach et al. 63790 (holotype MBM!) .

Tree 6–8 m high. Branchlets puberulent, sparsely lenticellate, finely striate; apical bud not observed; axillary buds puberulent. Leaves opposite to alternate, concentrated at the apex of the branches; stipules early deciduous, not observed; petioles 2–4 mm long, puberulent to glabrous, striate; leaf blade 7–23 cm long, 3.5– 11 cm wide, glabrous on both surfaces, elliptical or obovate, base cordate or cuneate, apex acuminate to cuspidate, margin entire; venation brochidodromus, midrib flat or slightly prominent on adaxial surface, prominent on abaxial surface; domatia absent. Inflorescences axillary or terminal, botryoid; peduncle 1–5 cm long, puberulent, not lenticelate, striate; bracts 2–2.5 mm long, ca. 2 mm. wide, pubescent, ovate, entire, persistent; bracteoles 2–2.5 mm long, ca. 0.5 mm wide, puberulent, filiform, entire, persistent; pedicels 6–20 mm long, puberulent, striate. Flowers with 4 sepals, covering the reproductive organs in the bud just before anthesis, 5–8 mm long, 2–4 mm wide, pubescent or puberulent on both surfaces, lanceolate, equal, entire, rarely ovate, uniseriate, apex acuminate; margin revolute, densely pubescent to tomentose on both surfaces; filaments 2–4 mm long, hirsute; anthers 2–3 mm long, pubescent, oblong; connective prolonged into a short acuminate awn, ca. 1 mm long, puberulent to glabrous; ovary ca. 2 mm long, short-pubescent, globose, sessile; style ca. 5 mm long, short-pubescent, straight, 4-fid at the apex; floral receptacle short-pubescent. Fruits not observed.

Habitat:—Savanna and Amazonian gallery forests.

Distribution:— Sloanea subsessilis occurs in Mato Grosso State, Brazil and in Bolivia.

Etymology:—From the Latin sub-, meaning not completely, a little; and from the Latin sessilis, meaning stalkless or apparently so, referring to the very short petioles (2–4 mm long).

Observations:— Sloanea subsessilis may be confounded with Sloanea floribunda Spruce ex Bentham (1861: 66) due to vegetative similarities such as entire leaf margins and blades completely glabrous on both species. It is also possible to point out some similarities between their leaf blade: obovate shape in S. floribunda , and elliptical or obovate shape in S. subsessilis ; 7.5–20 cm long in S. floribunda and 7–23 cm long in S. subsessilis ; base cordate or obtuse in S. floribunda and cordate or cuneate in S. subsessilis ; apex acuminate in S. floribunda and acuminate or cuspidate in S. subsessilis . However, these two species can be easily distinguished by the following characteristics: type of inflorescence (thyrsoid in S. floribunda vs. botryoid in S. subsessilis ), position of the ovary (stipitate in S. floribunda vs. sessile in S. subsessilis ), shape of the style (entire in S. floribunda vs. 4-fid at the apex in S. subsessilis ), and the size of the petiole (1.2–3.5 cm long in S. floribunda vs. 2–4 mm long in S. subsessilis ). Sloanea subsessilis has been collected in flower in October and February.

Paratype: BOLIVIA. Beni: Arroyo just N of Guayaramerin, Rio Mamor , Anderson 12078 ( K, NY) .

Figures

FIGURE 2. Sloanea subsessilis. A) Flowering branch; B) Detail of stamen; C) Detail of ovary (Hatschbach et al. 63790).