Amburana erythrosperma E. P. Seleme, C. H. Stirt. & V. F. Mansano, 2015

Seleme, Elidiene P., Lewis, Gwilym P., Stirton, Charles H., Sartori, Ângela L. B. & Mansano, Vidal F., 2015, A Taxonomic Review And A New Species Of The South American Woody Genus Amburana (Leguminosae, Papilionoideae), Phytotaxa 212 (4), pp. 249-263 : 259-260

3. Amburana erythrosperma E. P. Seleme, C. H. Stirt. & V. F. Mansano sp. nov. ( Figs. 5 & 6 )

Type:— BRASIL. Bahia: Livramento do Brumado, 13°43’S, 41°50’W, 25 March 1991, G. P. Lewis & S. M. M. de Andrade 1876 (holotype CEPEC 49450!, isotypes BR, K (2 sheets), sheet 2: K 000188278! (sheet 1 lacking barcode), MEXU 3588, MO 2844399!, NY 452223!).

Amburana erythrosperma differs from A. acreana and A. cearensis by having red seeds, and the membranous endocarp only partly developed, and not enveloping the seed(s).

Tree 5– 6 m. Stems smooth, reddish brown. Leaves 7–25 cm long; petiole 9–18 mm long; leaflets 7–13 per leaf, alternate, 2–5 × 2–3 cm, elliptic to ovate, base rounded, apex obtuse to retuse, adaxial surface glabrous, abaxial surface glabrous to puberulent, midrib raised abaxially. Inflorescence a congested panicle, terminal or axillary, 2–5 cm long; peduncle 1.5–3 cm long; flowers ca. 10–17 mm long; standard petal white, pinkish or yellowish, sericeous to pilose adaxially, 6–8 × 6–10 mm, base cordate, apex deeply emarginate, claw ca. 1 mm long; bracteoles ovate to triangular, apex acute, pilose; calyx campanulate, truncate, 1–2 mm long, scarcely toothed; tubular hypanthium 5–7 × 1 mm; stamen filaments 10, ascending, vexillary stamens 5, ca. 1 mm long, abaxial stamens 5, ca. 7 mm long; ovary ca. 4 × 1 mm, ovary stipe adnate to the hypanthium, densely pilose. Fruit linear-oblong, 5–8 × 0.6–1 cm, a membranous endocarp partly developed, but not surrounding the seed(s); seeds 1 (2) at the fruit base, 12–15 × 7–9 × 2–3 mm, red, shiny.

Distribution and habitat:— Amburana erythrosperma is endemic to South-Central Bahia, southern Chapada Diamantina, Brazil. Amburana erythrosperma and A. cearensis occur sympatrically in the southern Chapada Diamantina ( Fig. 7 ).

Phenology:— currently only known to flower in March and fruit in April.

Taxonomy:— Amburana erythrosperma is easily distinguishable from A. acreana and A. cearensis in fruit by its red seeds, with an endocarp only partly developed and not surrounding the seed(s) and the apex of the standard more prominently emarginate in A. erythrosperma .

Etymology:— The specific epithet refers to the red color of the seeds which contrasts markedly with the black seeds of the other two species.

Additional specimens examined (paratypes): — BRAZIL. Bahia: Livramento do Brumado, 27 km S de Livramento, próximo a duas comunidades Fazendinha e Itapicuru , 593 m, 13°53’S, 41°45’W, 22 April 1991, G. P. Lewis & S. M. M. Andrade 2002 ( BR, CEPEC, K, MBM, MEX, NY) ; Livramento do Brumado, cerca de 30 km na estrada de Brumado para Livramento do Brumado , 12 March 1991, H. S. Brito & G. P. Lewis 292 ( CEPEC, HUEFS, MBM, UEC) ; Livramento do Brumado, 10 km S de Livramento do Brumado para Brumado, lado esquerdo da estrada, 13°43’S, 41°50’W, 17 April 1991, G. P. Lewis & S. M. M. de Andrade 1997 ( CEPEC, K, NY) ; Livramento do Brumado, 10 km S de Livramento do Brumado para Brumado, lado esquerdo da estrada, 13°43’S, 41°50’W, 25 March 1991, G. P. Lewis & S. M. M. de Andrade 1876 ( BR, CEPEC, K, MEXU, MO, NY) .

Figures

FIGURE 5. Amburana erythrosperma. A. Flowers and flower buds; B. Fruits; C. Fruit and seeds (Photos: G. P. Lewis).

FIGURE 6. Amburana erythrosperma. A. Inflorescence; B. Leaf; C. Detail of leaflet lower surface; D. Flower buds; E. Standard (adaxial face); F. Longitudinal section of flower showing hypanthium, stamens and carpel; G.Anther; H. Gynoecium; J. Style and stigma; K. Calyx and hypanthium; L. Stamens; M. Flower, side view; N. Flower bud; P. Bracteole (abaxial face); Q. Fruit; R. Seed; S. Opened fruit showing two seeds (A–M from G. P. Lewis & S. M. M. de Andrade 1876; N–S from G. P. Lewis & S. M. M. de Andrade 1997). Artist unknown.

FIGURE 7. Geographical distribution of Amburana acreana (■), A. cearensis (●) and A. erythrosperma (▲). Map created using Diva GIS.