Parasenegalia santosii (G. P. Lewis) Seigler & Ebinger, 2017

Seigler, David S., Ebinger, John E., Riggins, Chance W., Terra, Vanessa & Miller, Joseph T., 2017, Parasenegalia and Pseudosenegalia (Fabaceae): New Genera of the Mimosoideae, Novon 25, pp. 180-205 : 189-191

4. Parasenegalia santosii (G. P. Lewis) Seigler & Ebinger , comb. nov.

Basionym: Acacia santosii G. P. Lewis, Kew Bull. 51(2): 371–372. 1996. Senegalia santosii (G. P. Lewis) Seigler & Ebinger in Seigler et al. , Phytologia 88(1): 72. [June] 2006. TYPE. Brazil. Bahia: 10–15 km along rd. Conquista to Anagé , caatinga, 22 Nov. 1972, T. S. dos Santos 2488 (holotype, CEPEC not seen [9 1 1 6]; isotype, K! [barcode] K 0 0 0 0 1 4 3 8, CEPEC photo at K! [bc] K 0 0 0 0 9 1 4 3 9, CEPEC photo at K [bc] K 000091440) . Figure 5 .

Tree to 6 m tall; bark not seen; twigs light brown to light gray, not flexuous, terete, glabrous to lightly puberulent; short shoots absent; prickles absent. Leaves alternate, 45–90 mm long; stipules brown, linear to subulate, symmetrical, flattened, straight, coriaceous, 4–7 mm long, 0.4–0.8 mm wide near the base, glabrous, tardily deciduous to persistent; petiole shallowly adaxially grooved, 20–25 mm long, glabrous; petiolar gland solitary, located just below to between the lowermost pinna pair, short-columnar, apex 0.3–0.5 mm across, bulbous, oval, glabrous; rachis shallowly adaxially grooved, 20–70 mm long, lightly pubescent, an orbicular to short-columnar gland 0.2–0.5 mm across between some of the pinna pair; pinnae 4 to 6 pairs/leaf, 35–85 mm long, 9–15 mm between pinna pairs; paraphyllidia 0.3–0.7 mm long; petiolule 3–6.5 mm long; leaflets 7 to 18 pairs/ pinna, opposite, 2.5–6.5 mm between leaflet pairs, oblong to obovate, 7–16 X 2.5–4.9 mm, glabrous, lateral veins obvious, 2 to 4 veins from the base, base oblique, mostly truncate on one side, margins not ciliate, apex obtuse, midvein submarginal to subcentral. Inflorescence a densely 25- to 40-flowered globose to subglobose head 10–14 mm across, in terminal pseudopaniculate clusters, the main axis to 250 mm long; peduncles 5–13 X 0.3–0.6 mm, densely puberulent; receptacle not enlarged, distinctly elongated; involucre 1 to 3 bracts located along peduncle, one usually located just below the globose inflorescence, early deciduous; floral bracts spatulate, 0.8–1.2 mm long, puberulent, early deciduous. Flowers sessile, white; calyx 5-lobed, 1.3–1.9 mm long, puberulent; corolla 5-lobed, 2.3–3 mm long, puberulent, lobes 1/4 the length of the corolla; stamens 40 to 80; stamen filaments 5.8–7.5 mm long, distinct; anther glands present; ovary glabrous, sessile to subsessile, the stipe to 0.2 mm long. Legumes not seen; seeds not seen.

Habitat and distribution. Parasenegalia santosii is known from savannas from near sea level to 400 m in Bahia and Minas Gerais, Brazil.

Phenology. Parasenegalia santosii flowers from

November through December.

IUCN Red List category. Parasenegalia santosii is assessed as Data Deficient (DD) at this time ( IUCN, 2001). This species is apparently rare and only known from a few collections, the type and three others. Further, because of habitat destruction, this species may at least be Vulnerable (VU), perhaps Endangered (EN).

Discussion. We have only examined three specimens of Parasenegalia santosii , a photograph, and a drawing of the type of this taxon. Two specimens from Bahia were seen by V. Terra. One additional collection has been reported to represent this species by Barros and Morim (2014) from Brazil (Espírito Santo, Aracruz, ES–445, Km. 10, fazenda Limoeiro, 19 ° 40 ' 36 '' S, 40 ° 0 9 ' 0 '' W, 4 Dec. 2014. H. Cavalcante de Lima 7 92 1 (RB RB6 1 2 2 4 0 [barcode] RB00905083). We have only seen an image of this collection. This specimen differs in several characters from the original description for P. santosii , e.g., the number of leaflets/pinna (17 to 20) and the position of the petiolar gland (on the petiole below the lowermost pair of pinnae). It seems probable that this species is more widespread than previously thought. In any case, additional collections are required to establish the range of character variation and occurrence of the species.

Lewis (1 9 9 6) suggested that Parasenegalia santosii (discussed as Acacia santosii ) is closely related to A. ambigua Vogel (≡ P. vogeliana Seigler & Ebinger ), a species from Hispaniola. Parasenegalia santosii is easily separated from other members of the genus with globose inflorescences by the elongated receptacle. This species also has a columnar petiolar gland, while other members of the genus have sessile petiolar glands. Although anther glands are reported as lacking (Lewis, 1 9 9 6), they are present on specimen M. Magalhães 19 4 9 2 (NY).

Specimens examined. BRAZIL. Bahia: Guaratinga, 8 Dec. 1966, R. P. Belém & R. S. Pinheiro 2748 (CEPEC); Prado, Estrada do camping, 31 Dec. 1979, L. A. Mattos & H. S. Brito 703 (CEPEC). Minas Gerais: caatinga, rodovia Río Bahia, Km. 811, a 10 km de Itaobim, 380 m, 9 Dec. 1958, M. Magalhaes˜ 19492 (NY, RB 40434).

Figures

Figure 5. Parasenegalia santosii (G. P. Lewis) Seigler & Ebinger. —A. Leaflet, abaxial surface. —B. Branch with pseudoracemose cluster and leaf. —C. Petiolar gland. —D. Flower. A–D from Magalhaes˜ 19492 (NY, RB 40434).