Acalypha poiretii Spreng.

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 : 470

40. Acalypha poiretii Spreng.

Systema vegetabilium 3: 879 ( Sprengel 1826). Ricinocarpus poiretii (Spreng.) Kuntze, Revisio Generum Plantarum 2: 618 ( Kuntze 1891). — Type: “Amer. trop.” s.loc., s.d., Anonymous s.n. (holo-, P-LAM[P00382110]).

ICONOGRAPHY. — Instituto de Botánica Darwinion (2022); Fig. 65D. ETYMOLOGY . — The epithet honors French naturalist Jean Poiret (1755-1834).

DISTRIBUTION AND HABITAT. — Native to the Americas. It has been reported from continental Africa ( Radcliffe-Smith 1978; Cardiel & Montero Muñoz 2018). Introduced in the Mascarene Islands ( Mauritius, La Réunion and Rodríguez) ( Fig. 61 ).

PRELIMINARY CONSERVATION ASSESSMENT. — Acalypha poiretii is widely distributed in the Americas, has a large EOO and AOO, a wide elevational range, and occurs in many different ecosystems. Therefore, we assess A. poiretii as Least Concern (LC).

MATERIAL EXAMINED. — 23 collections. Mauritius. Anonymous s.n. (G[G00324866]); Anonymous s.n. (P[P04779771]); Ayres, P.B. s.n. ( BR [BR0000014627545]), s.n. ( BR [BR0000014628016]); Boivin, L.H. s.n. (P[P04779760]); Bouton, L. s.n. (G[G00324860]); Cadet, Th. 2532 (P[P04779763]); Commerson, P. s.n. (P[P00678929]), s.n. (P[P04779769]), s.n. (P[P04779770]); Council of King’s College s.n. (K); Grey, D. s.n. (K); Herb. Richard s.n. (P[P04779773]); Jussieu, A. s.n. (P[P04779772]); Lahaie s.n. (P[P04779764]); Richard, M. 4 (P[P04779762]); Royal Botanical Gardens 164 (K); Vesco, M. s.n. (P[P04779765]); Webb, M. s.n. (G).

La Réunion. Barthe, M. s.n. (P[P04779768]); Boivin, L.H. s.n. (P[P04779774]); du Petit-Thouars, L.M.A. s.n. (P[P04779761]); Richard, M. 15 (P[P04779766]).

REFERENCES. — Baker (1877: 315); Cordemoy (1895: 312); Coode (1982: 79); Sagun et al. (2006: 124); Montero Muñoz et al. (2018a: 107).

DESCRIPTION

Annual herbs, to 0.5(-0.7) m tall, monoecious. Branches pubescent with simple, short, curved trichomes, long, erect trichomes, and glandular trichomes, glabrescent when mature. Axillary buds naked, pubescent with simple, short trichomes. Stipules to 2 mm long, triangular-lanceolate to subulate, sparsely hairy. Petioles slender, (0.5-)2-4(-5) cm long, indumentum similar to that on young branches. Leaf blades (2-)3-6(-8) × (1-) 1.5-4 cm, usually ovate-lanceolate, sometimes subrhombic, membranous; base rounded to subacute; apex acute to acuminate, acumen 4 mm long; acute; margin serrate to crenate-serrate, teeth obtuse, sometimes callose-edged; upper and lower surfaces laxly pubescent with simple, short, appressed trichomes on veins and sometimes with some glandular trichomes; margin ciliate; venation actinodromous, basal veins 5, secondary veins 4-5 per side. Stipels absent. Inflorescences spiciform, androgynous, axillary, to 3 cm long, mostly female with short male segment; peduncle to 1 mm long, pubescent with simple, curved, antrorse trichomes. Female segment densely flowered, to 2 cm long; bracts 16-20, sessile, enlarging in fruit to 5 × 6 mm, pubescent with simple trichomes to 1 mm long and some glandular trichomes; margin deeply dentate, teeth 7-8, to 1/3 bract length, narrowly triangular, central tooth not prominent; bracteoles absent. Male segment persistent, to 1 cm long; flowers glomerate; bracts to 0.5 mm long, oblong, ciliate. Male flowers: pedicel to 0.5 mm long, sparsely hairy; buds to 0.5 mm diameter, glabrous, papillose. Female flowers 1 per bract, sessile; sepals 3-4, to 0.5 mm long, ovate-lanceolate to oblong-lanceolate, ciliate; ovary c. 0.5 mm diameter, 3-lobed, smooth, surface pubescent with hyaline trichomes; styles 3, to 5 mm long, distinct, glabrous, each divided into 1-2 segments. Allomorphic flowers sometimes present at inflorescence apex; pedicel filiform, to 3 mm long, pubescent with simple, hyaline trichomes to 1 mm long; sepals 3, to 0.5 mm long, ovate-lanceolate, ciliate with simple, short trichomes; ovary 1-lobed, to 2.5 × 2 mm, densely pubescent with simple, flattened, hyaline trichomes to 0.5 mm long, distally fimbriate; style 1, to 2 mm long, glabrous. Capsules to 2 mm diameter, smooth, surface pubescent with simple, short, hyaline trichomes and some simple, erect trichomes to 1 mm long. Seeds c. 2 × 1 mm, pyriform, minutely foveolate.

Figures

FIG. 65. — Mature female bracts: A, Acalypha perrieri Leandri (R. Decary 15792); B, A. pervilleana Baill.(J. J. Floret 682); C, A. pervilleana (J. M. Hildebrandt 3356); D, A.poiretii Spreng.(L. Boivin s.n.); E, A. rabesahalana I.Montero & Cardiel (H.Humbert 32480); F, A. radula Baker (Service Forestier Madagascar 45-SF); G, A.richardiana Baill. (M. Richard 224); H, A. rottleroides Baill. (L. Nusbaumer LN2629). Illustration by Iris Montero Muñoz. Scale bars: A, D, E, G, H, 1 mm; B, C, F, 2 mm.

FIG. 61. — Distribution map of Acalypha poiretii Spreng.in Mascarene Islands.