Abrahamia delphinensis Randrian. & Lowry 2017, spec. nova

7. Abrahamia delphinensis Randrian. & Lowry, spec. nova (Fig. 6).

Typus: MADAGASCAR. Prov. Toliara: Rég. Anosy, Vinanibe, W de Fort-Dauphin, [25°03’S 46°56’E], 7.XII.1968, fr., Service Forestier 28606 (holo-: P [P06774807]!; iso-: G [G00341712]!, K!, MO- 5056712!, NY!, P [P00580305, P00580306]!, TEF [TEF000883]!)

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Diagnosis

Abrahamia delphinensis Randrian. & Lowry is easily distinguished from its congeners by its semicraspedodromous secondary veins, its thin petiole, and its fruits densely covered with short indument.

Description

Trees 5-12 m tall, 20-21 cm DBH, bark with white latex; tips of young twigs with short, appressed indument. Leaves opposite or sub-opposite; blade obovate, 2.8-5.8-(6) 3 1-3 cm, chartaceous, apex retuse, margins entire, base broadly cuneate, adaxial surface glabrous, abaxial surface sparsely strigose on midvein, venation semicraspedodromous, midvein prominent abaxially, secondary veins 18-25 pairs, 2-3 mm apart, raised and prominent abaxially, slightly raised adaxially, tertiary veins visible only on abaxial surface; petiole 7-15 mm, c. 0.5-1 mm in diam., usually glabrous but sometimes with very sparse short, appressed indument. Inflorescence axillary or terminal, a panicle, 1.5-5.5 cm long, pubescent. Male and female flowers small, 4-merous, c. 2 mm long; calyx lobes 0.5 3 1 mm, triangular, adaxial surface glabrous, abaxial surface pubescent; corolla lobes c. 2 3 1-1.2 mm, ovate, adaxial surface glabrous, abaxial surface pubescent. Male flowers with filaments 1-1.2 mm long, pubescent or sometimes glabrous, anthers c. 0.5-0.8 mm, subglobose, glabrous; disk slightly cupuliform, c. 1.5 mm in diam., glabrous; ovary completely absent. Female flowers with vestigial stamens, filaments c. 1 mm long, pubescent, anthers very small, c. 0.2 mm, sterile; disk glabrous, cupuliform, c. 1.5 mm in diam.; ovary c. 0.6-0.8 3 1 mm, depressed ovoid, completely covered with indument; style very short, inserted apically, partly covered with indument, stigmas capitate. Fruits 2.3-2.5 3 1.2-1.4 cm, ellipsoid, densely covered with short, appressed and slightly tangled indument, with longitudinal striations.

Distribution, ecology and phenology

Abrahamia delphinensis occurs in low elevation humid forest, including littoral forest on sand, and is restricted to the area around Fort Dauphin (Map 2). It flowers between September and November, and fruits between October and December.

Conservation status

With an EOO of 1442 km 2, a minimum AOO of 48 km 2, and 12 known localities representing a total of 7 locations, 3 of which are situated within protected areas (Andohahela, Mandena, and Sainte Luce) while the others are variously subjected mining as well as fire and land clearing leading to a projected decline in all 5 sub-criteria, A. delphinensis is assigned a preliminary conservation status of “Vulnerable” [VU B1ab(i,ii,iii,iv,v)+2ab (i,ii,iii,iv,v)] using the IUCN Red List Categories and Criteria (IUCN, 2012).

52 Boissiera 71

Notes

Abrahamia delphinensis most closely resembles A. lenticellata but can be distinguished by its retuse (vs short acuminate to acuminate) leaf apex and the complete absence (vs presence) of a rudimentary ovary in male flowers.

Paratypi

MADAGASCAR. Prov. Toliara: Andohahela PN, NW of Tolagnaro, 24°45’S 46°51’E, 250-500 m, 17-20.X.1992, fl., Malcomber et al. 1678 (BM, CAS, G, K, MO [2 sheets], NY, P, TAN, US, WAG); N of Fort-Dauphin, near Ste. Luce, 24°47’S 47°10’E, 10 m, 21.X.1989, y. fr., McPherson 14196 (MO, P, TAN, TEF); Mandena, botanical garden, 24°57’S 47°00’E, 25 m, 25.X.1989, fl., McPherson et al. 14244 (MO, P, TAN, TEF); Ste. Luce, N de Mahatalaky, 0-10 m, 28.IV.1989, ster., Rabevohitra 1959 (MO, P, TAN); Andohahela PN, Isaka-Ivondro, 24°47’S 46°50’E, 0-500 m, 10-27.IX.1993, fl., Randriamampionona 631 (A, BM, BR, BRIT, CAS, F, G, K, MO [2 sheets], NY, P [2 sheets], PRE, S, TAN, US, W, WAG, Z); Andohahela PN, Andranolava, 24°41’S 46°45’E, 28.VIII.1996, ster., Randriamampionona 1338 (MO, P, TAN); Mandena forestry station, 24°57’S 47°00’E, 0-10 m, 18.XI.1996, ster., A. Randrianasolo 546 (MO, P, TAN); N of Tolagnaro, Ste. Luce area, [24°47’S 49°09’E], 0-10 m, 19.XI.1996, ster., A. Randrianasolo 569 (MO, P, TAN); Bevoay, Androranga, [24°29’39’’S 47°05’39’’E], 171 m, 18.XI.2009, fr., Razakamalala 4680 (G, MO, P, TAN); Ifarantsa, Ivorona, 24°29’09’’S 47°04’43’’E, 35 m, 10.XII.2010, fr., Razakamalala 5033 (G, K, MO, P, TAN); Mandena, [24°57’S 47°00’E], 16.XI.1948, fl., Réserves Naturelles 1348 (G, MO, P); ibid. loco, 18.IX.1950, Service Forestier 1545 (P, TEF); Marofanenitra, 25.IX.1951, Service Forestier 4043 (P, TEF); Mandena, [17°30’S 48°38’E], 29.X.1953, fl., Service Forestier 7826 (P, TEF); ibid. loco, 3.IX.1953, fl., Service Forestier 8170 (MO, P, TEF); Col du Maningotry, 300-400 m, 27.IX.1953, fl., Service Forestier 8510 (G, MO, P, TEF); Mandena, 15.XII.1954, fr., Service Forestier 15622 (MO, P, TEF).