34. Acalypha mayottensis I.Montero & Cardiel

PhytoKeys 140: 65 (Montero Muñoz et al. 2020b). —

Type: Mayotte. Mamoudzou commune, îlot M’bouzi, 12°48’50”S, 45°14’08”E, 10-50 m, 22.XI.2000, J.-N. Labat, F. Barthelat, C.M. Hladik & A.B. Sifary 3268 (holo-, G [G00034240] ; iso-, K, MAO, MO [MO-2965774], P [P00209719]). — Paratypes: Mayotte. Mamoudzou commune, îlot M’Bouzi, 12°48’57”S, 45°14’06”E, 90 m, 22.XI.2000, J.-N. Labat, F. Barthelat, C.M. Hladik & A.B. Sifary 3272 (G [G00034255], K, MAO, MO [MO-2966248], P [P00209724, P00209725]) ; îlot M’Bouzi, 12°48’39”S, 45°14’06”E, 26.XII.2002, F. Barthelat, A. de Vanssay & G. Rembert 1112 (MAO, P [P00339165]) . — Precise location unknown, probably from M’Bouzi islet, 01.I.2010, G. Viscardi 310 (HKM, P [P02439826]) .

ICONOGRAPHY. — Montero Muñoz et al. (2020b); Figs 54F; 57E.

ETYMOLOGY. — The epithet refers to Mayotte island, to which the small Mbouzi islet belongs, and to which this species appears to be endemic.

DISTRIBUTION AND HABITAT. — Endemic to Comoros Archipelago (Mayotte). Dry forest and secondary forest. Altitudinal range 10- 90 m (Fig. 53).

PRELIMINARY CONSERVATION ASSESSMENT. — Acalypha mayottensis is only known from Mbouzi islet. Its EOO and AOO are estimated to be 8 km 2. Mbouzi islet was declared a “Réserve Naturelle Nationale” in 2007, a category IV protected area (Dudley 2008). In the 1990s the islet had lost 70% of its original forests to agriculture. Mbouzi now conserves 10% of its natural and secondary forest. Currently, the most serious threat are invasive species, both animals, such as Eulemur fulvus, and plants, such as Antigonon leptopus, Lantana strigocamara, Leucaena leucocephala, Litsea glutinosa, Spathodea campanulata and Furcraea foetida (Boullet & Traclet 2018; Quintard et al. 2019). Due to its restricted geographic range and the threats from alien species, A. mayottensis is assigned a preliminary conservation status of Critically Endangered: CR B2ab(ii,iii).

MATERIAL EXAMINED. — 4 collections. Mayotte. Barthelat, F. 1112 (MAO, P[P00339165]); Labat, J.-N. 3268 (G[G00034240], K, MAO, MO[MO-2965774], P[P00209719]), 3272 (G[G00034255], K, MAO, MO[MO-2966248], P[P00209724, P00209725]); Viscardi, G. 310 (P[P02439826]).

DESCRIPTION

Shrubs, deciduous, to 5 m tall, monoecious. Branches laxly pubescent with simple, erect trichomes to 1 mm long, glabrous when mature. Axillary buds ovoid, to 3 × 2.3 mm, perulate, perules 2, imbricate, chartaceous, blackish, glabrous. Stipules to 6 mm long, linear to triangular-lanceolate, becoming filiform when mature, margins scarious, sparsely hairy, glabrescent, and with some glands. Petioles slender, (2-)3-5(-6) cm long, pubescent with simple, curved, antrorse trichomes. Leaf blades 5-10 × 3-6 cm, ovate-lanceolate to elliptic-lanceolate, membranous; base rounded to subcordate; apex subacuminate to acuminate, acumen to 15 mm long, rounded; margin crenulate-serrulate to subentire, slightly revolute, teeth rounded; upper surface pubescent with simple, thin, erect trichomes, glabrescent; lower surface indumentum similar to that on upper surface but denser; axils of secondary veins with minute, sparsely hairy, pocket-shaped domatia, sometimes with hair-tuft domatia; margins ciliate in sinuses; venation actinodromous, basal veins 3, secondary veins 4-6 per side. Stipels absent. Inflorescences spiciform androgynous, axillary, to 6 cm long, mostly male with short female segment; peduncle thick, to 15 mm long, laxly pubescent with trichomes similar to those on young branches, glabrescent. Female segment to 2.5 cm long; bracts 1-2, sessile, enlarging in fruit to 19 × 21 mm, subreniform, veins and margin sparsely hairy with simple, erect trichomes to 1.5 mm long, glabrescent; margin crenate to subentire, sometimes dentate in young bracts, central tooth not prominent; bracteoles absent. Male segment persistent, to 4 cm long; flowers glomerate; bracts to 0.5 mm long, triangular, sparsely hairy. Male flowers: pedicel to 1 mm long, glabrous; buds to 0.7 mm diameter, sparsely hairy with simple, arachnoid trichomes. Female flowers 1 per bract, sessile; sepals 3[4], to 0.7 mm long, ovate-triangular, sparsely hairy with simple, arachnoid trichomes; ovary c. 1 mm diameter, 3-lobed, echinate, projections and surface hispid; styles 3, to 3 mm long, distinct, rachis thick, appressed-pubescent, each divided into 8-10 segments. Allomorphic flowers not seen. Capsules to 4 mm diameter, erinaceous projections conical, subacute, to 1 mm long, they and surface hispid with simple, erect trichomes to 1 mm long. Seeds 2.5 × 2 mm, pyriform, minutely foveolate.