Acalypha magistri 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 : 459

32. Acalypha magistri I.Montero & Cardiel

South African Journal of Botany 146: 640 ( Montero Muñoz et al. 2022). — Type: Madagascar. Sava region (Antsiranana prov.), au nord d’Andapa , dans la Réserve naturelle intégrale de Marojejy, aux environs du sommet d’Ambatosoratra , 1583 m, 14°32’S, 49°42’E, 17-24.VI.1994, D. Ravelonarivo 273 (holo-, MO; iso-, ILLS, MAUAM, P, TAN) .

ICONOGRAPHY. — Montero Muñoz et al. (2022); Fig. 57D.

ETYMOLOGY. — The epithet honors teachers at the Alonso de Ercilla High School (Ocaña, Toledo, Spain), where the first author studied. The epithet magistri is a nominative plural noun.

DISTRIBUTION AND HABITAT. — Endemic to Madagascar (Sava). Medium altitude evergreen moist forest. On basement rocks, 1583 m altitude ( Fig. 51 ).

PRELIMINARY CONSERVATION ASSESSMENT. — Acalypha magistri is known only from one collection from Marojejy. Its EOO could not be calculated; its AOO is estimated to be 8 km 2. Marojejy has been a protected area since 1952, and a National Park since 1998 (Category II; Dudley 2008). The main threats that affect the Marojejy forests are illegal logging of precious wood, uncontrolled fires, and mining for topaz and beryl, mainly at the boundaries of the National Park. However, at the high elevations where this species occurs (it was collected near the top of Ambatosoratra peak), habitat disturbance from ecotourism likely is the only threat ( Patel 2007; Almeda & Ranarivelo 2019). In view of its limited AOO, Acalypha magistri is assigned a preliminary conservation status of Vulnerable: VU D2. MATERIAL EXAMINED. — 1 collection. Madagascar: Ravelonarivo, D. 273 (MAUAM, MO).

DESCRIPTION

Small trees, leaf persistence unknown, to 6 m tall, monoecious. Branches pubescent with simple, short, erect trichomes, glabrescent when mature. Axillary buds ovoid, to 1.5 × 0.7 mm, perulate, perules 2, imbricate, chartaceous, dark brown, glabrous. Stipules to 2 mm long, triangular-lanceolate, apex acute, base with some sparse, simple trichomes, margin ciliate with simple, short trichomes. Petioles 1.2-3.5 cm long, indumentum similar to that on young branches. Leaf blades 7.5-12 × 2-5.5cm, elliptic-lanceolate to ovate-lanceolate, subchartaceous; base rounded; apex acuminate, acumen to 13 mm long, acute; margin serrate, teeth acute; upper surface subglabrous, with simple, short, erect, simple trichomes, especially on veins; lower surface indumentum similar to that on upper surface but denser; margin ciliate; venation pinnate, secondary veins 6-8 per side. Stipels absent. Inflorescences spiciform, androgynous, axillary, to 9.5 cm long, mostly male with a female segment; peduncle to 22 mm long, it and rachis pubescent with simple, curved, antrorse trichomes. Female segment to 3.7 cm long; bracts 4, sessile, enlarging in fruit to 5 mm diameter, orbicular, pubescent with simple, erect trichomes to 0.5 mm long; margin subentire to crenate, central tooth not prominent; bracteoles absent. Male segment persistent, to 3.8 cm long; flowers glomerate; bracts to 0.7 mm long, triangular, sparsely hairy. Male flowers: pedicel to 0.5 mm long, sparsely hairy; buds not seen. Female flowers 1 per bract, sessile; sepals 3, to 1.5 mm long, triangular-lanceolate, sparsely hairy; ovary not seen; styles 3, to 3 mm long, distinct, sparsely hairy. Allomorphic flowers not seen. Capsules to 5 mm diameter, echinate, projections conical, to 2 mm long, surface pubescent with simple, short, erect trichomes. Seeds c. 4 × 3 mm, pyriform, minutely foveolate.

Figures

FIG. 57. — Mature female bracts: A, Acalypha leptomyura Baill. (J.-N. Labat & T. Deroin 2320); B, A. levinii I.Montero & Cardiel (L. Gillespie 10809); C, A. linearifolia Leandri (G. Cours 4638); D, A. magistri I.Montero & Cardiel (D. Ravelonarivo 273); E, A. mayottensis I.Montero & Cardiel (J.-N. Labat, F. Barthelat, C.M. Hladik & A.B. Sifary 3272); F, A. medibracteata Radcl.-Sm. & Govaerts (R. Decary 16103); G, A. menavody (Leandri) I.Montero & Cardiel (M. Bardot-Vaucoulon 1016); H, A. nusbaumeri I.Montero & Cardiel (L. Nusbaumer LN1169). Illustration by Iris Montero Muñoz. Scale bars: A, C, D, F, H, 1 mm; B, E, G, 2 mm.

FIG. 51. — Distribution map of Acalypha magistri I.Montero & Cardiel in Madagascar.