Abrahamia Randrian. &amp; Lowry 2017, gen. nov.
Creators: name: Randrianasolo, Armand
name: Lowry II, Porter P.
name: Schatz, George E.
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Sapindales
Anacardiaceae
Abrahamia

description: <i>Abrahamia</i> Randrian. &amp; Lowry, gen. nov. Typus: <i>Abrahamia ditimena</i> (H. Perrier) Randrian. &amp; Lowry (≡ <i>Protorhus ditimena</i> H. Perrier). <b>Diagnosis</b> <i>Dioecious trees or shrubs. Leaves simple, persistent, opposite, subopposite, verticillate or alternate, chartaceous, subcoriaceous or coriaceous, lateral veins parallel, arcuate, forming an obtuse to acute angle with the midrib toward the base of the blade. Inflorescence erect, a thyrse or panicle. Flowers (4-)5(-6)-merous; pedicel short, articulated; sepals much smaller than petals; stamens alternipetalous, filament broadened at the base (sterile in female flowers, forming staminodes), anthers dorsifixed, introrse, glabrous; ovary pubescent or glabrous (rudimentary or absent in male flowers), with 1 locule containing a single subpendulous or pendulous ovule. Fruits drupaceous, ellipsoidal or ovoid, symmetrical or slightly asymmetrical, resiniferous; seeds ruminate; cotyledons usually inseparable (except in Abrahamia ibityensis (H. Perrier) Randrian. &amp; Lowry, in which the resiniferous canals are only peripheral).</i> <b>Description</b> Dioecious <i>trees</i> or <i>shrubs</i>; bark with white, translucent or red resinous latex. <i>Leaves</i> alternate, opposite or subopposite (verticillate in one species), simple, coriaceous, subcoriaceous or chartaceous, persistent (deciduous in <i>A. humbertii</i>). Venation pinnate, craspedodromous or semicraspedromous, midvein usually flat, rarely very slightly raised above, prominently raised below (rarely on both surfaces), secondary veins parallel or nearly so, straight or arcuate, prominent below or on both surfaces, forming an obtuse to acute angle with the midrib toward the base of the blade. <i>Inflorescence</i> terminal and/ or axillary, an erect thyrse or panicle, or intermediate and forming a paniculiform thyrse. <i>Flowers</i> usually 5-merous (sometimes 4- or 6-merous); sepals much smaller than petals; stamens 5 or 4 (rarely 6), alternipetalous, filaments straight, flattened, broadened at the base, inserted basally on the outer surface of the disk, anthers dorsifixed, introrse, dehiscent with longitudinal slits (stamens reduced in size and sterile in female flowers, forming staminodes); disk usually cupuliform and crenulate in <i>male flowers</i>, annular and cupuliform in <i>female flowers</i>; ovary with 1 locule containing a single pendulous or subpendulous or ovule on a short funiculus, placentation subapical (ovary rudimentary or absent in male flowers); style one, short, apically trifid or unbranched with 3 capitate stigmatic lobes. <i>Fruits</i> drupaceous, ellipsoidal or ovoid, symmetrical or slightly asymmetrical, exocarp usually with longitudinal striations on surface, glabrous or velutinous, mesocarp resinous, endocarp thin, papyraceous; seed solitary, with resiniferous canals throughout (only peripheral in <i>A. ibityensis</i>), ruminate; cotyledons usually inseparable (separable in <i>A. ibityensis</i>). 14 Boissiera 71 <i>Etymology</i> The genus is named in honor of the late Jean Prosper Abraham (1936-1996), a wellknown Malagasy forester with a remarkable knowledge of the woody plants of Madagascar and who contributed much to our knowledge of the island’s rich and diverse flora. <i>Notes</i> <i>Abrahamia</i> includes a total of 34 species, all endemic to Madagascar, including 15 species formerly placed in <i>Protorhus</i> (e.g., by PERRIER DE LA BâTHIE, 1944, 1946), to which 19 additional species are newly described here. With the recognition of <i>Abrahamia</i> as a separate genus, <i>Protorhus</i> is now restricted to a single species in Africa, <i>P. longifolia</i>. The two genera differ in several flower and fruit characters, as indicated by PELL (2004) and PELL et al. (2011), and summarized in Table 1. <i>Abrahamia</i> is represented in all of Madagascar’s major vegetation types (MOAT &amp; SMITH, 2007) and broad bio-climatic zones (CORNET, 1974; SCHATZ, 2000). Species can be found in humid forest in the eastern and Sambirano regions <i>(A. antongilensis, A. sambiranensis),</i> wooded grassland and bushland in the center of the island <i>(A. ibityensis, A. buxifolia),</i> western dry forest <i>(A. deflexa, A. humbertii),</i> and southwestern subarid spiny forest-thicket (<i>A. phillipsonii</i> Randrian. &amp; Lowry). Members of the genus occur on many types of substrate and at a wide range of elevations, from littoral forest on sand at the sea level (<i>A. nitida</i> (Engl.) Randrian. &amp; Lowry, <i>A. suarezensis</i> Randrian. &amp; Lowry) to humid forest on lateritic soil at altitudes up to 2000 m <i>(A. buxifolia, A. itremoensis).</i> Species of <i>Abrahamia</i> were described by PERRIER DE LA BâTHIE (1946) as polygamo-dioecious, indicating that he interpreted them as having both unisexual and hermaphroditic flowers on the same individual. However, careful observation has shown that all members of the genus are functionally dioecious. Female flowers have rudimentary, sterile stamens that are reduced in size, whereas male flowers either have an ovary that is rudimentary and non-functional or lack an ovary altogether. 16 Boissiera 71 <b>Key to the species of Abrahamia</b> [Numbers in parentheses indicate the previous coupLet Leading to the present one] 1. Leaves completely glabrous on both surfaces (occasionally with extremely small indument visible only under a dissecting microscope on or adjacent to the midvein on the abaxial surface)...................................................................................................... 2 1a. Leaves with at least a few evident trichomes, sometimes restricted to the midvein beneath..................................................................................................................... 20 2. Leaves usually verticillate (3 per node, sometimes one leaf broken off but leaving a scar); E coast littoral forest (occasionally to 200 m elevation).............................. 23. <i>A. nitida</i> 2a. Leaves alternate or opposite to subopposite................................................................. 3 3. Largest leaf blade at least 15 cm long........................................................................... 4 3a. Largest leaf blade less than 15 cm long (rarely to 17 cm in <i>A. oblongifolia</i> and <i>A. littoralis</i>).................................................................................................................. 6 4. Petiole stout, c. 4-5 mm in diam.; young branches with corky bark; littoral and low elevation humid forest, Maroantsetra S to Tampolo................................ 15. <i>A. latifolia</i> 4a. Petiole slender, no more than 2(-2.5) mm in diam.; young branches without corky bark; humid forest................................................................................................................ 5 5. Largest leaf with c. 50-60 pairs of secondary veins; fruits ellipsoid, covered with dense, short indument; Betampona.......................................................... 2. <i>A. betamponensis</i> 5a. Largest leaf with c. 30-45 pairs of secondary veins; fruits obovoid, glabrous; Lokobe and Tsaratanana........................................................................................19. <i>A. lokobensis</i> 6 (3). Leaves elliptic to ovate (rarely a few slightly obovate), broadest at the middle or in the proximal part of the blade........................................................................................... 7 6a. Leaves obovate to oblanceolate, nearly all broadest in the distal part of the blade......... 11 7. Leaves narrowly elliptic to narrowly ovate (rarely a few slightly obovate), at least (2.5-) 3 times as long as wide; dry forest, Isalo to Andohahela....................27. <i>A. phillipsonii</i> 7a. Leaves elliptic to ovate, sometimes broadly so (rarely a few slightly obovate), no more than 1.5-2 times as long as wide.................................................................................. 8 8. Fruits covered with dense short indument; flowers 4-merous (rarely 5-merous); humid forest, Marojejy and Anjanaharibe-Sud S to Ranomafana and Ivohibe......................................................................................................................................17. <i>A. lenticellata</i> 8a. Fruits glabrous; flowers 5-merous (unknown in <i>A. darainensis</i>)................................... 9 9 (8). Leaves orbicular to broadly elliptic (rarely a few broadly ovate), blades no more than 2 times as long as wide, subcoriaceous, apex rounded (rarely broadly acute); dry forest, calcareous substrates, Ankarana, Bemaraha.........................................12. <i>A. humbertii</i> 9a. Leaves elliptic to ovate (occasionally a few broadly ovate or obovate), most blades at least 2 times as long as wide, chartaceous, apex acute to acuminate.......................... 10 10. Blade of largest leaf to c. 6.5 cm long, often discolorous, the upper surface dark green to chocolate brown, apex emarginate or rounded to acute; dry western forest (Bemaraha, Ketsepy, Antsalova, Marovoay, Mahajanga)................................................ 6. <i>A. deflexa</i> 10a. Blade of largest leaf c. 8 cm long, concolorous, the upper surface drying grayish green, apex acuminate; humid forest, Daraina............................................... 5. <i>A. darainensis</i> 11 (6). Largest leaf with 40-70 pairs of secondary veins; humid eastern forest...... 30 <i>A. sericea</i> 11a. Largest leaf with 10-40 pairs of secondary veins........................................................ 12 12. Inflorescences all axillary; leaves alternate; E coast littoral forest, Tampolo S to Mahabo............................................................................................................... 18. <i>A. littoralis</i> 12a. Inflorescences terminal and sometimes also axillary; leaves opposite to subopposite........13 13. Tertiary venation obscure on abaxial surface............................................................. 14 13a. Tertiary venation visible on abaxial surface, at least toward the margins....................16 14. Secondary veins closely spaced, 6-9 pairs per cm in median portion of largest leaf, blade distinctly glaucous on adaxial surface, nearly always strongly discolorous when dry, often chocolate brown above (sometimes obscured by glaucescence); fruit velutinous (sometimes glabrescent); dry forest, central high plateau, Itremo, Ibity, Ambatofinandrahana............................................................................................................................3. <i>A. buxifolia</i> 14a. Secondary veins widely spaced, 3-5 pairs per cm in median portion of largest leaf, blade neither glaucous (sometimes weakly so in <i>A. suarezensis</i>) nor strongly discolorous when dry, various shades of green but not chocolate brown above; fruit glabrous............... 15 15. Largest leaf with 15-30 pairs of secondary veins, margins distinctly revolute; trees 15-20 m tall; littoral and dry forest, Mt. d’Ambre, S of Vohémar and Masoala........................................................................................................................................ 28. <i>A. revoluta</i> 15a. Largest leaf with 12-15 pairs of secondary veins, margins slightly thickened but not revolute; trees to 10(-12) m tall; N dry and coastal forests, Antsiranana, Vohémar, Daraina............................................................................................. 31. <i>A. suarezensis</i> 16 (13).Leaves with venation craspedodromous, secondary veins all clearly reaching the margin (rarely a few terminating away from the margin in <i>A. oblongifolia</i>).............................. 17 16a. Leaves with venation semicraspedodromous, at least some secondary veins branching and not reaching the margin...................................................................................... 19 18 Boissiera 71 17 (16).Largest leaf with 40-70 pairs of secondary veins, largest blade 9-15 cm long..................................................................................................................... 30. <i>A. sericea</i> 17a. Largest leaf with 15-33 pairs of secondary veins, largest blade 2.5-7.5(-8.5) cm long...................................................................................................................................... 18 18. Blade of largest leaf at least (4.5-) 5 cm long, coriaceous, rigid; mature fruit 2-3 × 1.4-1.6 cm............................................................................................................... 8. <i>A. ditimena</i> 18a. Blade of largest leaf no more than 4-(4.5) cm long, subcoriaceous, not rigid; mature fruit 1-1.5 × 0.5-0.8 cm............................................................................21. <i>A. minutifolia</i> 19 (16).Largest leaf blade 8-14(-17) cm long, petiole c. 2 mm in diam.; fruits glabrous; dry to humid forest, Nossi Be, Antsiranana area.......................................... 24. <i>A. oblongifolia</i> 19a. Largest leaf blade 3.5-6 cm long, petiole c. 0.5-1 mm in diam.; fruits with short dense indument; littoral forest and low-elevation humid forest, Tolagnaro area............................................................................................................................... 7. <i>A. delphinensis</i> 20 (1). Blade of largest leaf at least 10 cm long...................................................................... 21 20a. Blade of largest leaf no more than 10 cm long.......................................................... 34 21. Largest leaves with at least 40 pairs of secondary veins..............................................22 21a. Largest leaves with fewer than 40 pairs of secondary veins........................................26 22. Inflorescences all axillary...........................................................................................23 22a. Inflorescences terminal and sometimes also axillary..................................................24 23. Leaves with evident tertiary venation, apex flat; fruits glabrous; humid forest, Marojejy, Anjanaharibe-Sud, Masoala, Rantabe, Ambalabe.................................. 10. <i>A. elongata</i> 23a. Leaves lacking evident tertiary venation, apex usually folded in pressed material; fruits pubescent when young, glabrescent at maturity; humid forest, Ambilobe, Ampondrabe, Ambato, Kalabenono-Galoka, Ambanja, Andavakoera................ 29. <i>A. sambiranensis</i> 24 (22).Secondary veins in median portion of leaf blade closely spaced, c. 5-6 per cm; fruit with dense indument; humid eastern forest..................................................... 30. <i>A. sericea</i> 24a. Secondary veins in median portion of leaf blade more widely spaced, c. 3 per cm; fruit glabrous or with evident indument............................................................................25 25. Leaves with an acute to short acuminate apex (rarely a few rounded); fruits with dense, short indument; flowers 4-merous (rarely 5-merous); humid forest........................................................................................................................................ 17. <i>A. lenticellata</i> 25a. Leaves with a broadly acute to rounded or retuse apex; fruits glabrous; flowers 5-merous; dry forest...........................................................................................11. <i>A. grandidieri</i> 26 (21).Inflorescences all axillary...........................................................................................27 26a. Inflorescences terminal and sometimes also axillary..................................................29 27. Abaxial surface of leaves with dense, erect to spreading light brown lanate indument................................................................................................................. 34. <i>A. viguieri</i> 27a. Abaxial surface of leaves glabrous or with spare, short indument..............................28 28. Longest petiole 5-10 mm; eastern humid, low to mid-elevation forest... 16. <i>A. lecomtei</i> 28a. Longest petiole (18-) 20-30 mm; E coast littoral forest, Tampolo S to Mahabo.............................................................................................................................18. <i>A. littoralis</i> 29 (26).Leaf apex long acuminate to nearly caudate, blade chartaceous.................................30 29a. Leaf apex acute to retuse or emarginate, sometimes short-acuminate (acumen &lt;1 cm long), blade chartaceous to subcoriaceous or coriaceous.......................................... 32 30. Abaxial surface of leaves densely covered with reddish-brown lanate indument, venation craspedodromous; eastern littoral forest to premontane forest on sand or laterite, Maroantsetra, Toamasina, Zahamena PN, Fort-Carnot........................... 34. <i>A. viguieri</i> 30a. Abaxial surface of leaves glabrous or with scattered, white sericeous indument, venation semi-craspedodromous.............................................................................................31 31. Adaxial surface of leaves always glabrous, widest blade to 3.5(-4) cm; fruit velutinous; eastern humid forest.........................................................................17. <i>A. lenticellata</i> 31a. Adaxial surface of leaves glabrous or with scattered white appressed indument, widest blade at least 4 cm; fruit glabrous; north-eastern humid forest, Masoala, Maroantsetra.........................................................................................................1. <i>A. antongilensis</i> 32 (29).Leaves with 10-20 pairs of widely spaced secondary veins, only 1 or 2 per cm in median portion of blade; eastern and north-eastern humid forest, Maroantsetra, Manongarivo, Andapa, Sambava, Ranomafana, Mantadia, Zahamena..................... 32. <i>A. thouvenotii</i> 32a. Leaves with 20-40 pairs of narrowly spaced veins, 2-6 per cm in median portion of blade........................................................................................................................33 33. Leaves obovate, never more than 2.5 times as long as wide, coriaceous; inflorescences terminal and sometimes also axillary; fruits covered with dense indument; humid eastern forest.......................................................................................... 8. <i>A. ditimena</i> 33a. Leaves oblanceolate (sometimes narrowly elliptic), at least 3 times as long as wide, chartaceous to coriaceous, flexible; terminal and axillary; fruits glabrous; along rivers and streams, western and southern Madagascar, Ambanja, Befandriana Nord, Ambalavao, Ihosy, Sakaraha, Amboasary, Ampanihy.............................................11. <i>A. grandidieri</i> 34 (20).Largest leaves with at least 40 pairs of secondary veins..............................................35 34a. Largest leaves with fewer than 40 pairs of secondary veins........................................36 20 Boissiera 71 35 (34).Second
description: Published as part of <i>Randrianasolo, Armand, Lowry II, Porter P. &amp; Schatz, George E., 2017, Taxonomic treatment of Abrahamia Randrian. &amp; Lowry, a new genus of Anacardiaceae from Madagascar, pp. 1-152 in Boissiera 71</i> on pages 13-30, DOI: 10.5281/zenodo.7618113
description: {"references": ["PELL, S. K. (2004). Molecular Systematics of the Cashew Family (Anacardiaceae). Ph. D. dissertation, Louisiana State University, Baton Rouge.", "PELL, S. K., J. D. MITCHELL, A. J. MILLER &amp; T. A. LOBOVA (2011). Anacardiaceae. In: KUBITZKI, K. (ed.), The Families and Genera of Vascular Plants 10: 7 - 50. Springer Press, London.", "CORNET, A. (1974). Essai de cartographie bioclimatique a Madagascar. Notice explicative N \u00b0 55. ORSTOM, Paris.", "SCHATZ, G. E. (2000). Endemism in the Malagasy tree flora. In: LOURENcO, W. R. &amp; S. M. GOODMAN (ed.), Diversity and endemism in Madagascar: 1 - 9. Memoires de la Societe de Biogeographie, Paris."]}