Acalypha gillespieae G.A.Levin & I.Montero

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 : 438-439

17. Acalypha gillespieae G.A.Levin & I.Montero

PhytoKeys 140: 59 ( Montero Muñoz et al. 2020b). — Type : Mada - gascar. Reg. Diana [Prov. Antsiranana], Montagne des Français , E of Antsiranana ( Diego Suarez ), 12°19’26.4”S, 49°20’16.6”E, 258 m, 31.X.2012, L. J. Gillespie, G. A. Levin, J. Andriatiana & W. M. Cardinal-McTeague 10692 (holo-, MO; iso-, CAN, K, P, TAN). — Paratypes: Madagascar. Reg. Diana [Prov. Antsiranana], Montagne des Français, E of Antsiranana (Diego Suarez), 12°19’26.4”S, 49°20’16.6”E, 258 m, 31.X.2012, L. J. Gillespie, G. A. Levin, J. Andriatiana & W. M. Cardinal-McTeague 10693 ( CAN, MO, P, TAN); 12°19’S, 49°20’E, 200- 300 m, 2.XII.1990, L. J. Gillespie 4097 (K, ILLS, MO, P[P00324524], TAN) .

ICONOGRAPHY. — Montero Muñoz et al. (2020b); Fig. 35E.

ETYMOLOGY. — The epithet honors Dr. Lynn J. Gillespie, research scientist at the Canadian Museum of Nature. In addition to studying Arctic plants and Poaceae , she has worked on the systematics of Euphorbiaceae worldwide, including in Madagascar. She collected all known specimens of this species, either alone or as leader of a team of botanists.

DISTRIBUTION AND HABITAT. — Endemic to Madagascar (Diana). Dry deciduous forest. On sandstone. Altitudinal range 200-300 m ( Fig. 32 ).

PRELIMINARY CONSERVATION ASSESSMENT. — Acalypha gillespieae is known from three collections from the same locality and appears to be a narrow endemic known only from Montagne des Français. Montagne des Français has been relatively well collected (P. Lowry pers. comm.), so the dearth of collections suggests this species is rare, even there. Its apparent rarity could also, at least in part, reflect it being quite inconspicuous and thus easily overlooked. The EOO could not be calculated, and its AOO is estimated to be 8 km 2. Montagne des Français is a category V protected area ( Dudley 2008), but the habitat is somewhat threatened by wood-cutting, primarily for charcoal, but mainly on its lower slopes, below the altitude where A. gillespieae is found. Acalypha gillespieae is assigned a preliminary conservation status of Critically Endangered: CR B2ab(ii,iii,iv).

MATERIAL EXAMINED. — 3 collections. Madagascar: Gillespie, L. 4097 ( ILLS, MO, P[P00324524], TAN), 10692 ( CAN, MO, P, TAN), 10693 ( CAN, K, MO, P, TAN).

DESCRIPTION

Shrubs, deciduous, to 3 m tall, intricately branched, monoecious. Branches densely pubescent with simple, short, straight, antrorsely appressed trichomes proximally and antrorsely curved trichomes distally, glabrescent when mature. Axillary buds spherical, c. 2 mm diameter, perulate, perules 2, imbricate, chartaceous, brownish, glabrous. Stipules to 2-3.5 mm long, subulate, densely pubescent with simple, short, spreadingascending trichomes. Petioles slender, 2-5 mm long, densely pubescent with simple, curved, antrorse trichomes. Leaf blades 1.5-4 × 1-3 cm, elliptic to obovate, membranous, unlobed or (2-)3-lobed; base rounded to broadly obtuse; apex obtuse; margin crenate, teeth rounded; upper surface sparsely pubescent with simple, straight, erect to antrorse trichomes; lower surface indumentum similar to that on upper surface but denser; venation somewhat prominent on both surfaces, actinodromous,, basal veins 3, secondary veins 2-3 per side. Stipels absent. Inflorescences spiciform, androgynous, axillary, c. 1 cm long, mostly male with 1 female bract at base; peduncle thin, 2-3 mm long, it and rachis densely pubescent with curved, antrorse trichomes. Female segment: bract 1, sessile, enlarging in fruit to 5 × 9 mm, subreniform, sparsely pubescent with simple, straight, antrorse trichomes; margin entire; bracteoles absent. Male segment persistent, to 3.5 mm long; flowers glomerate; bracts to 0.3 mm long, triangular, densely pubescent with simple, slender, flexuous trichomes. Male flowers: pedicel to 0.4 mm, glabrous; buds not seen. Female flowers 1 per bract, sessile; sepals 3, c. 0.75 mm long, rounded-deltate, ciliate with simple, slender, flexuous trichomes to 0.5 mm long; ovary not seen; styles 3, c. 2 mm long, slightly connate at base, rachis stout, pubescent with simple, short, straight, antrorse trichomes, each style divided into 5-8 segments. Allomorphic flowers not seen. Capsules to 3 mm diameter, echinate, projections conical, to 0.75 mm long, surface hispid with simple, straight, erect to antrorse trichomes to 0.5 mm long. Seeds 2 × 1.5 mm, pyriform, smooth.

Figures

FIG. 35. — Mature female bracts: A, Acalypha decaryana Leandri (R. Decary 2985); B, A. emirnensis Baill. (G. McPherson 14590); C, A. filiformis Poir. (P. Commerson s.n.); D, A. fimbriata Schumach. & Thonn. (J. Audru 40466); E, A. gillespieae G.A.Levin & I.Montero (L. Gillespie et al. 10692); F, A. gracilipes Baill. (R. Rabevohitra 2054); G, A. humbertii Leandri (W. Kaudern 222). Illustration by Iris Montero Muñoz. Scale bars: A, C-G, 1 mm; B, 2 mm.

FIG. 32. — Distribution map of Acalypha gillespieae G.A.Levin & I.Montero in Madagascar.