Acalypha ankaranensis I.Montero & Cardiel

Muñoz, Iris Montero, Levin, Geoffrey A. & Cardiel, José María, 2023, Monograph of Acalypha L. (Euphorbiaceae) of the Western Indian Ocean Region, with the description of a new species from Mayotte, Adansonia (3) 45 (26), pp. 395-496 : 420

4. Acalypha ankaranensis I.Montero & Cardiel

South African Journal of Botany 146: 635 ( Montero Muñoz et al. 2022). — Type: Madagascar. Diana region [Antsiranana prov.]: Ambilobe, Réserve Spéciale d’Ankarana. Piste vers le campement des Anglais et la sortie de la réserve, 180 m, 12°54’43”S, 49°06’39”E, 19.II.1994, M. Andrianarisata et al. 41 (holo-, P[P00508496]; iso-, MO[MO-2965838]). — Paratypes: Madagascar. Diana region [Antsiranana prov.]: Mahamasina. Réserve Spéciale d’Ankarana ,

chemin du canyon forestier, 130 m, 12°55’25”S, 49°06’39”E, 16.I.2003. M. Bardot-Vaucoulon et al. 1209 (K, MO, P[P00455503], TAN); Ankarana Res., near Campement des Anglais , 150 m, 12°54’S, 49°08’E, 30.I.1994, A. J. M. Leeuwenberg et al. 14374 ( BR [ BR0000021450266 ], E, G, K, LMU, MA, MO, P[P04779850], PRE, TAN, WAG) .

ICONOGRAPHY. — Montero Muñoz et al. (2022); Fig. 24B.

ETYMOLOGY. — The epithet refers to the Ankarana massif ( Madagascar), to which this species appears to be endemic.

DISTRIBUTION AND HABITAT. — Endemic to Madagascar (Diana), Ankarana massif. Dry deciduous forest on Mesozoic limestone. Altitude c. 180 m ( Fig. 16 ).

PRELIMINARY CONSERVATION ASSESSMENT. — Acalypha ankaranensis is only known from Ankarana massif, where this species appears to be a narrow endemic. Its EOO and AOO are estimated to be 12 km 2. The Ankarana massif is a Special Reserve, established in 1956; and it is a category IV protected area ( Dudley 2008). The reserve lost 20% of its dry deciduous forests and 85% of its moist evergreen forest from 1996 to 2016, and is threatened mainly by sapphire mining, and by agriculture (commercial cash crops), logging, and locally by fires to improve grazing ( Wilson et al. 1988; Kull 2000; Goodman et al. 2018). In recognition of its restricted geographic range and the cited threats, A. ankaranensis is assigned a preliminary conservation status of Critically Endangered: CR B2ab(ii,iii,iv).

MATERIAL EXAMINED. — 3 collections. Madagascar. Andrianarisata, M. 41 (K, MO[MO-2965838], P[P00508496]); Bardot-Vaucoulon, M. 1209 (P[P00455503]); Leeuwenberg, A.J.M. 14374 ( BR [BR0000021450266], E, G, K, LMU, MA[MA-01-00849822], MO, P[P04779850], PRE, TAN, WAG[WAG.1578695, WAG.1578696]).

DESCRIPTION

Shrubs, probably deciduous, to 1.2 m tall, monoecious. Branches red-tinged, pubescent with simple, curved, antrorse trichomes, glabrescent when mature. Axillary buds ovoid, to 1 mm long, perulate, perules 2, overlapping (superposed), membranous, scarious, appressed-pubescent, margin with sessile glands. Stipules to 5 mm long, lanceolate to linear-lanceolate, apex acute, sparsely hairy with simple, short trichomes, margin with simple, erect trichomes to 1.5 mm long and short, glandular trichomes. Petioles reddish, 3-5 cm long, indumentum similar to that on young branches and with simple, erect trichomes to 1.5 mm long. Leaf blades (6-)7- 9 × 3.5-5.5 cm, broadly ovate-lanceolate, membranous; base subcordate to cordate; apex acuminate, acumen to 20 mm long, acute; margin serrate, teeth acute, with sessile glands at apex; upper surface laxly pubescent with simple, erect trichomes to 1.5 mm long, and with simple, curved trichomes on veins; lower surface laxly pubescent with sparse, simple, short trichomes, and with simple, curved trichomes on veins, axils of the secondary veins with pocket-shaped domatia; venation prominent on both surfaces, actinodromous, basal veins 5, secondary veins 5-6 per side. Stipels filiform, to 1 mm long, sparsely hairy. Inflorescences spiciform, androgynous, and solitary female bracts, mainly axillary, some androgynous inflorescences terminal. Androgynous inflorescences to 5.5 cm long, mostly male with short female segment; sessile or subsessile; rachis indumentum similar to that on petioles. Female segment to 3.5 cm long; bracts 1-4, sessile, enlarging in fruit to 8 × 10 (-18) mm, reniform, sparsely hairy with simple, erect trichomes to 1 mm long, especially at margin; margin dentate to denticulate, with c. 14 teeth, teeth acute to subacute, with sessile glands at apex, central tooth not prominent; bracteoles to 0.5 mm long, lanceolate, sparsely hairy. Male segment persistent, to 4 cm long, proximal 2 cm sterile; flowers glomerate; bracts to 0.8 mm long, oblong, sparsely hairy. Solitary female bracts sessile, similar to those on androgynous inflorescences. Male flowers: pedicel to 0.5 mm long, sparsely hairy; buds to 0.8 mm diameter, sparsely hairy, papillose. Female flowers 1 per bract, sessile; sepals 3, to 0.7 mm long, triangular, sparsely hairy, margin with some sessile glands; ovary c. 1 mm diameter, 3-lobed, apparently smooth, surface hispid with simple, erect trichomes to 1.5 mm long; styles 3, to 6 mm long, slightly connate at base, sparsely hairy on rachis, each divided into c. 10 segments. Allomorphic flowers sometimes present, axillary; pedicel filiform, to 20 mm long, sparsely hairy; sepals 3, similar to those of normal flowers; ovary immature. Capsules to 3 mm diameter, papillose-hispid, papillae triangular, to 0.5 mm long, ending in a simple trichome to 1 mm long, surface pubescent with simple, short trichomes. Seeds c. 1.2 mm diameter, subglobose, apiculate, foveolate.

Figures

FIG. 24. — Mature female bracts:A, Acalypha andringitrensis Leandri (H. Perrier de la Bâthie 13640); B, A. ankaranensis I.Montero & Cardiel (A. J. M. Leeuwenberg 14374); C, A. bailloniana Müll.Arg. (G. Viscardi 439); D, A. boinensis Leandri (R. Ramananjanahary 115); E, A. burmanii I.Montero & Cardiel (P. Commerson s.n.); F, A. cardielii I.Montero & G.A.Levin (J. Leandri 115); G, A. chibomboa Baill. (F. Barthelat 1436); H, A. claoxyloides Hutch. (F. Friedmann 5633). Illustration by Iris Montero Muñoz. Scale bars: A, 2 mm; B-H, 1 mm.

FIG. 16. — Distribution map of Acalypha ankaranensis I.Montero & Cardiel in Madagascar.