Dalbergia bemarivensis Phillipson & N. Wilding, 2021

Wilding, Nicholas, Phillipson, Peter B. & Crameri, Simon, 2021, Taxonomic studies on Malagasy Dalbergia (Fabaceae). II. A new name for D. mollis and the reinstatement of D. chermezonii, Candollea 76 (2), pp. 251-257 : 252-256

Dalbergia bemarivensis Phillipson & N. Wilding , nom. nov.

 Dalbergia mollis Bosser & Rabev. in Bull. Mus. Natl. Hist. Nat., B, Adansonia 18: 211. 1996 [nom. illeg.].  Dalbergia stenocarpa R. Vig. in Notul. Syst. (Paris) 14: 182. 1952 [nom. illeg.] [non D. stenocarpa Kurz, 1875 ].

[A: Service Forestier 109-R-130; B, D: Bernard & Randrianaivo 2749; C: Ramamonjiarisoa 54; E: Ramananjanahary 104; F: Du Puy et al. M422;

G: Rakotovao & Ravololomanana 7460; H–I: Service Forestier 29081; J: Service Forestier 2681].

Lectotypus (fi r s t s t e p d e s i g n a t e d by B O S S E R & RABEVOHITRA, 1996: 211; second step designated here): MADAGASCAR. Reg. Melaky [Prov. Mahajanga]: Boina, bassin du Haut Bemarivo, 400 m, X.1906, Perrier de la Bâthie 4355 ( P [ P00060377 ]!; isolecto-: P [ P00060376 , P00060378 , P00060379 ]!; K [ K000379264 ]!) .

Trees to c. 35 m tall or shrubs; bole to 15 m high, DBH to 102 cm. Branches densely covered in a whitish or yellow-brown to golden, or less frequently reddish, tomentose indument, yellow-green in vivo (black in sicco) when young, becoming glabrous, pale grey-brown when old, lenticels present. Leaves alternate, (12–) 15–30 cm long, with (11–)13–19 alternate leaflets; petiole and rachis pale yellow-green in vivo, light to dark brown in sicco, tomentose at first, glabrescent; petiole 1.8–3.5 cm long; stipules caducous, 8–12 × 2–3 mm; leaflets (20–)30–80(–95) × (8–) 15–32 mm, decreasing in size towards the proximal part of the leaf, the distal leaflet slightly longer than the rest; petiolule 2–4 mm long, pale brown to yellow-green in vivo, light to dark brown in sicco, tomentose; lamina elliptical to broadly elliptical, lanceolate, oblong or rarely obovate, at times orbicular in smaller proximal leaflets, thinly coriaceous, base rounded or narrowly to broadly cuneate, margin plane to slightly revolute, apex obtuse or acute, weakly retuse or sometimes emarginate, venation eucamptodromous, with c. 6– 12 lateral veins per side; upper and lower surface bright mid-green in vivo, dull green to brown in sicco, upper surface matt, glabrescent, the midrib forming a groove, the lower surface matt, tomentose, higher-order veins forming a fine network, midrib prominent. Inflorescences terminal, a panicle, 5–11 cm long, composed of 1 to many compact, sparsely branched paniculate units, each subtended by a well-developed pinnate leaf-like bract or reduced, caducous, scale-like bract, terminal axes of the inflorescence usually long, curved, secundiflorous and sub-spicate, with flowers in 2 adjacent rows with alternating insertion, the axes densely yellowish-brown pubescent; peduncle to 5 cm long. Flowers subtended by a caducous, puberulous, triangular scale-like bract, 0.6–1.2 × 0.3–0.4 mm; pedicel 0.1–1 mm long, puberulous; bracteoles ovate to elliptic, 1–1.2 × 0.3–0.4 mm, apex acute, sparsely puberulous, yellow to orange-brown in sicco, caducous; calyx yellow-green, sometimes dark purple at the base in vivo, becoming yellow to reddish-brown or black in sicco, sparsely puberulous, persisting on fruits, 3–4 mm long, fused in the lower 2/3, the 2 upper lobes fused to form a single, rounded unit, c. 1.5 × 3 mm, the apex shallowly emarginate, the 2 lateral lobes acute-triangular, c. 1.3 × 1.2 mm, the lowest lobe acute-triangular, keeled, c. 1.8 mm × 1.5 mm; petals glabrous, white in vivo becoming orange in sicco; standard petal pandurate, 3.5–6(–7) × 2.5–3.5(–5) mm, claw 1–1.5 mm long, apex notched; wing petals 4–5.5(–6.7) × 1.5–2(–2.7) mm, claw 1–1.3 mm long; keel petals 4–5(–5.8) × 1.6–2(–2.3) mm, claw 1.5–2 mm long; androecium glabrous, monadelphous, 4–5(–6) mm long; stamens 9–10, filaments free for upper 1/5–1/3; gynoecium 4–6 mm long, sparsely covered in long yellowish hairs; stipe 2–3 mm long; ovary c. 2 mm long, with up to 3 ovules; style c. 1 mm long. Fruits pale-yellow green in vivo, red-brown in sicco, the body elongate-elliptical, 7.5–12 × 1.5–3.0 cm when single-seeded, or 15– 16 cm long when multi-seeded, base cuneate, apex acute or rounded, surface densely longitudinally ribbed, glabrous; stipe 4–10 mm long, glabrescent; style caducous; seeds (immature) sub-reniform, flattened, brown, 8–9 × 5 mm.

Vernacular names and uses. – “Hazotana” (Réserve Naturelles 5371), “Manary” (Karatra et al. 286, Réserves Naturelles 6646, Service Forestier 109-R-130), “Manary Bomby” (= “Manaribomby”) (Service Forestier 3350, 19241), “Manary Mavo” (= “Manarimavo”) (Hassold et al. 729, Service Forestier 6849), “Manary Toloho” (= Manaritoloho) (Service Forestier 5518, 52-R-78), “Manary Vazanomby ” (Ramamonjiarisoa 54), “Manary Voraka” (Réserve Naturelles 2014, 2540), “Sandraza” (Service Forestier 3468).

Dalbergia bemarivensis is reportedly used in the making of furniture and the production of charcoal.

Distribution, ecology and phenology. — Dalbergia bemarivensis is known from the dry and subhumid bioclimatic zones in the northwest, throughout the Boeny Region, in the northern part of the Betsiboka Region and in the southern part of the Sofia Region, especially in the interior, and as far east as Mandritsara, at elevations from 0– 900 m. Its range does not appear to overlap with that of D. chermezonii , and neither species is known from the Melaky Region, which separates their known ranges. The species grows on sandy and rocky substrates in seasonally dry forest and woodland. Flowering occurs from August to October.

Conservation status. — Based on an integrated approach ( WILDING et al., 2021), combining past and projected forest decline together with an ecological niche model for the species, we estimate the decline in habitat quality for Dalbergia bemarivensis , over the period 1990–2089 and based on a generation time of 33 years, to be 89 %, assuming no habitat is lost within protected areas (IUCN Categories I–IV). Dalbergia bemarivensis is therefore assigned a preliminary conservation status of “Critically Endangered” [CR A4(c)] following IUCN Red List Categories and Criteria (IUCN, 2012).

Notes. — Bosser & Rabevohitra did not designate a single sheet among the five separately mounted duplicates of Perrier de la Bâthie 4355 at P to serve as the lectotype. We select the only specimen of this collection at P annotated “ Vig. det.” and “[envoyé] à Vig. 3/18” to serve as the lectotype of D. bemarivensis . Based on these annotations, this specimen is the most likely to have been seen by Réné Viguier. The species has been collected twice recently at Marotandrano at c. 900 m , contrasting with older records, which are all from below 400 m.

Dalbergia chermezonii R. Vig. in Notul. Syst. (Paris): 14: 182. 1952.

Lectotypus (designated here): MADAGASCAR. Reg. Ihorombe [Prov. Fianarantsoa]: vallée de la Fandramanana [ E d’Ihosy ], III.1912, Perrier de la Bâthie 4202 ( P [ P00064116 ]!, isolecto-: P [ P00064115 , P00064117 ]!) .

= Dalbergia stenocarpa var. menabeensis R. Vig. in Notul. Syst. 14: 182. 1952  Dalbergia mollis var. menabeensis (R. Vig.) Bosser & R. Rabev. in Bull. Mus. Natl. Hist. Nat., B, Adansonia 18: 211. 1996 [nom. illeg.]. Holotypus: MADAGASCAR. Reg. Menabe [Prov. Mahajanga]: Belo sur Tsiribihina , bois sablonneux près de la mer. X.1913, Perrier de la Bâthie 4795 ( P [ P00064091 ]!, iso-: P [ P00064092 ]!) .

showing lanceolate leaflets. Dalbergia chermezonii R. Vig. : C. Inflorescence, flowers and young leaves showing the tomentose indument on the leaves and inflorescence axes; D. Mature leaves and young fruit, showing ovate leaflets.

[A: Rakotovao et al. 7412; B: Razakamalala & Andrianarivelo 8749; C: Bernard & Andrianarivelo 2819; D: Rakotovao 6678]

[Photos: A, D: C. Rakotovao; B, C: S. Andrianarivelo]

Trees to c. 16 m tall or shrubs; bole to 10 m, DBH to 40 cm. Branches densely covered in a yellow-brown to golden, or less frequently reddish, tomentose indument, yellow-green in vivo (black in sicco) when young, becoming glabrous, pale grey-brown when old, lenticels present. Leaves alternate, (5.5–) 9–18 cm long, with (3–)7–11(–13) alternate leaflets; petioles and rachis pale green in vivo, light to dark brown in sicco, tomentose, glabrescent; petiole 9–25 mm long; stipules caducous, 8–12 × 2–3 mm; leaflets (12–)17–66(–80) × 9–39(–45) mm, decreasing in size towards the proximal part of the leaf, the distal leaflet longer than the rest; petiolule 1.5–3(–7) mm long, pale green-brown in vivo, light to dark brown in sicco, tomentose; lamina broadly ovate, obovate, broadly elliptic, rarely obcordate or suborbicular, at times orbicular in smaller proximal leaflets, thinly coriaceous, base rounded to cuneate, margin plane to revolute, apex cuspidate to rounded, acute to obtuse, sometimes shallowly emarginate, venation eucamptodromous, with c. 6–12 lateral veins per side; upper and lower surface bright mid-green in vivo, dull green to brown in sicco, upper surface matt or glossy, glabrescent, the midrib forming a groove, the lower surface matt, tomentose, higher-order veins forming a fine network, midrib prominent. Inflorescences terminal, a compact panicle, 4–10 cm long, composed of 4–6 racemose branches, subtended by a well-developed pinnate leaf-like bract or reduced, caducous, scale-like bract, terminal axes of the inflorescence usually long, curved, secundiflorous and sub-spicate, with flowers in 2 adjacent rows with alternating insertion, the axes densely yellowish-brown pubescent; peduncle to 5 cm long. Flowers subtended by a caducous, puberulous, triangular scale-like bract, 0.9–1.1 × 0.6–0.7 mm; pedicel 0.1–1.5 mm long, puberulous; bracteoles ovate to elliptic, 1.2–1.8 × 0.6–0.7 mm, apex acute, sparsely puberulous, yellow to orange-brown in sicco, caducous; calyx yellow-green, sometimes dark purple at the base in vivo, becoming yellow to reddish-brown or black in sicco, sparsely puberulous, persisting on fruits, 3–4.5 mm long, fused in the lower 1/3–2/3, the 2 upper lobes fused to form a single, rounded unit, c. 1.3 × 1.9 mm, the apex shallowly emarginate, the 2 lateral lobes acute-triangular, c. 1.5 × 1.4 mm, the lowest lobe acute-triangular, keeled, c. 1.8 mm × 1.3 mm; petals glabrous, white to yellow in vivo becoming orange in sicco; standard petal pandurate, (4–)5–6 × 3–3.5(–4) mm, claw 1–1.5 mm long, apex notched; wing petals 4–6 × (1.3–) 1.6–1.8 mm, claw 1–1.5 mm long; keel petals 3.6–4(–5.5) × 1.7–2 mm, claw 1.5–2 mm long; androecium glabrous, monadelphous or diadelphous, 2.5–5 mm long; stamens 9–10, or more rarely 9+1, filaments free for upper 1/3–1/5 or rarely completely free; gynoecium 3.5–5(–5.7) mm long, sparsely covered in long yellowish hairs; stipe 1.2–2 mm long; ovary c. 2 mm long, with up to 3 ovules; style 0.5–1.7 mm long. Fruits pale-yellow green in vivo, red-brown in sicco, the body elongate-elliptical, 4.5–7 × (0.9–) 1.2–1.9 cm when single-seeded, or 8.5–10 cm long when multi-seeded, base cuneate, apex acute or rounded, surface densely longitudinally ribbed, glabrous; stipe 2–7 mm long, glabrescent; style caducous; seeds not seen.

Vernacular names and uses. — “Behoditra” (Service Forestier 11-R-180), “Manary” (= “Magnary”) (Bernard & Andrianarivelo 2802, 2818, 2819, Ravelonarivo et al. 4575, Service Forestier 8390, 9333), “Manary Toloho” (= “Manery toloho”, “Manarin toloho”, “Manarintoloho”, “Magnary Toloho”) (Josso et al. 7, Herb. Jard. Bot. Tan. 6311, Rabarimanarivo et al. 238, Service Forestier 9254, 11936, 12700, 12952, Seyrig 325b), “Manary Tomboditotse” (Service Forestier 15025), “Manary Fotsy” (Service Forestier 13246), “Manary ravimboanjo” (Rakotovao 6678, 6697), “Manary Vato” (Service Forestier 13249), “Voamboana” (Service Forestier 45-R-222).

Dalbergia chermezonii is reported to have medicinal value post-pregnancy, however, no further information is available regarding precisely what it is used to treat. It is also reportedly used for carpentry, notably to make furniture. Its use for charcoal production is also strongly suspected.

Distribution, ecology and phenology. — Dalbergia chermezonii is known from the subhumid, dry and subarid bioclimatic zones in the south and southwest of Madagascar, from Belo sur Tsiribihina at the north of its range in the Menabe Region to Antanimora in the south in the Androy Region, and as far east as the Horombe Plateau in the Ihorombe Region, at elevations to c. 1350 m, but it appears to be largely absent from the driest areas at low elevations in the subarid zone from Toliara to Ambovombe. The species grows on sandy and rocky substrates in seasonally dry forest and woodland. Flowering occurs from October to February.

Conservation status. — Based on an integrated approach ( WILDING et al., 2021), combining past and projected forest decline together with an ecological niche model for the species, we estimate the decline in habitat quality for Dalbergia chermezonii , over the period 1990–2089 and based on a generation time of 33 years, to be 88 %, assuming no habitat is lost within protected areas (IUCN Categories I–IV). Dalbergia chermezonii is therefore assigned a preliminary conservation status of “Critically Endangered” [CR A4(c)] following IUCN Red List Categories and Criteria (IUCN, 2012).

Notes. — Among the three duplicates of Perrier de la Bâthie 4202 at P, we select the only specimen of this collection annotated “[envoyé] à Vig. 3/18” to serve as the lectotype of D. chermezonii . Based on these annotations, this specimen is the most likely to have been seen by Réné Viguier.