Acalypha baretiae 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 : 417-418

2. Acalypha baretiae I.Montero & Cardiel

South African Journal of Botany 119: 420 ( Montero Muñoz et al. 2018b). — Type: Madagascar. Toliara. Morondava, 10 km de Morondava, route de Malaimbandy, 337 m, 20°23’33”S, 44°56’57”E, X.1963, M. J. Bosser 18124 (holo-, P[P04779795]). — Paratypes: Madagascar, Toliara: Atsimo-Andrefana region. Beroroha , fokontany Betorabato. Village le plus proche Ambalamanga. Forêt Akolitsika (rivière), 276 m, 21°40’22”S, 44°59’36”E, 18.I.2011. R. Razakamalala 6064 ( MO [MO-3025026], P[P01152840], TAN) .

ICONOGRAPHY. — Montero Muñoz et al. (2018b).

ETYMOLOGY. — The epithet honors Jeanne Baret (1740-1807), the first woman to circumnavigate the globe. Disguised as a man and calling herself Jean Baret, she served as naturalist Philibert Commerson’s valet and botanical assistant on Louis Antoine de Bougainville’s expedition from 1766 to 1769, the first French circumnavigational voyage. She visited Madagascar with Commerson in 1770-1772, and when Commerson died in Mauritius (1773) she returned to France with all the material that they had collected ( Knapp 2011). DISTRIBUTION AND HABITAT. — Endemic to Madagascar (Menabe and Atsimo-Andrefana). Dry deciduous forest and dry spiny thickets. Sandstone. Altitudinal range 276-350 m ( Fig. 14 ).

PRELIMINARY CONSERVATION ASSESSMENT. — Acalypha baretiae is only known from two collections. Its EOO could not be calculated; its AOO is estimated to be 8 km 2. Both collections of A. baretiae were made in unprotected areas. This species grows in dry deciduous forest in southwestern Madagascar (see assessment of A. diminuta ). The habitat of this species continues to be lost, so A. baretiae is preliminarily assessed as Critically Endangered: CR B2ab(ii,iii,iv). MATERIAL EXAMINED. — 2 collections. Madagascar. Bosser, M.J. 18124 (P[P04779795]); Razakamalala, R.6064 (MO[MO-3025026], P[P 01152840]).

DESCRIPTION

Shrubs, probably deciduous, to 2-3 m tall, monoecious. Branches sometimes thorny, pubescent with simple, short, antrorse trichomes, glabrescent when mature; brachyblasts present. Axillary buds ovoid, to 2 × 1 mm, perulate, perules 2, valvate, membranous, brownish, puberulent with simple, short trichomes and ciliate. Stipules to 3.5 mm long, triangular-lanceolate, midrib prominent, margin ciliate, apex with simple, long trichomes. Leaves alternate or congested on brachyblasts. Petioles 0.3-0.8 cm long, pubescent with simple, short, curved trichomes, sometimes also with simple, erect trichomes to 0.7 mm long. Leaf blades (2-)3-4 × 1-2(-2.3) cm, elliptic to obovate, chartaceous; base acute to subcuneate; apex obtuse; margin crenate to serrate, slightly revolute, teeth rounded to obtuse, with minute papillae at apex; upper surface glabrescent, with some simple, short trichomes on the veins; lower surface indumentum similar to that on young branches, axils of the secondary veins with hair-tuft domatia; venation actinodromous, basal veins 3, secondary veins 3-4 per side. Stipels absent. Inflorescences racemose or paniculate, gynecandrous, axillary, to 7 cm long, about equally male and female; peduncle 5-10(- 15) mm long, it and rachis pubescent with simple, short, arachnoid trichomes. Male segment persistent, 2-3(-3.5) cm long; flowers glomerate; bracts to 0.7 mm long, triangular-lanceolate, ciliate and with some sparse, simple trichomes. Female segment 2-3.5 cm long; bracts 3-9, not enlarging in fruit, to 0.7 mm long, triangular, margin ciliate and with minute papillae; bracteoles absent. Male flowers: pedicel to 0.5 mm long, sparsely hairy; buds to 0.5 mm diameter, sparsely hairy. Female flowers 2-3 per bract, pedicellate; pedicel to 5 mm long, glabrous; sepals 5, to 1 mm long, narrowly triangular, slightly fleshy, ciliate; ovary c. 1 mm diameter, 2-lobed, densely papillose-echinate with thick capitate papillae, surface glabrous; styles 2, to 3 mm long, connate at thickened base, glabrous, each divided into c. 15 slender segments. Allomorphic flowers not seen. Capsules to 5 mm diameter, papillose, papillae to 0.5 mm long, capitate, surface glabrous. Seeds c. 2.3 × 1.8 mm, subglobose, minutely foveolate.

NOTE

This is the only species from Madagascar that belongs to subg. Hypandrae; the other species are found on continental Africa.

Figures

FIG. 14. — Distribution map of Acalypha baretiae I.Montero & Cardiel in Madagascar.