Acalypha bailloniana Müll.Arg.

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 : 421-422

5. Acalypha bailloniana Müll.Arg.

Linnaea 34: 44 ( Müller Argoviensis 1865). — Ricinocarpus baillonianus (Müll.Arg.) Kuntze, Revisio Generum Plantarum 2: 617 ( Kuntze 1891). — Acalypha indica var. bailloniana (Müll.Arg.) Hutch. , Flora of Tropical Africa 6 (1): 904 ( Hutchinson 1912). — Type: Tanzania. Zanzibar: s.l., 1848, L. H. Boivin s.n. (holo-, P[P04809900]).

ICONOGRAPHY. — Fig. 24C.

ETYMOLOGY. — The epithet honors French botanist Henri Ernest Baillon (1827-1895).

DISTRIBUTION AND HABITAT. — Native to East Tropical Africa. Probably introduced in the Comoros Archipelago (Anjouan and Grande Comoro), weedy and associated with cultivated areas ( Fig. 17 ).

PRELIMINARY CONSERVATION ASSESSMENT. — Acalypha bailloniana is assessed preliminarily as Data Deficient (DD), pending revision of the continental African material.

MATERIAL EXAMINED. — 4 collections. Comoros Archipelago. Boivin, L.H. s.n. (P[P00196288]); Kirk, T. 8179 (K); Viscardi, G. 438 (P[P00852762]), 439 ( HCD, P00852763).

REFERENCES. — Montero Muñoz et al. (2018a: 93).

DESCRIPTION

Herbs, to 50 cm tall, monoecious. Branches pubescent with simple, short, curved, antrorse trichomes and some short, glandular trichomes, prominently ribbed and glabrescent when mature. Axillary buds naked, pubescent with simple, short trichomes. Stipules to 4 mm long, triangular-lanceolate, pubescent with simple, short trichomes, margin with some sessile glands. Petioles (1-)1.8-2.8(-3) cm long, indumentum similar to that on young branches. Leaf blades 1.5-3.1 × (0.7-) 1-2 cm, rhombic to ovate-lanceolate, membranous; base acute; apex acute; margin serrate, teeth acute; upper surface laxly pubescent with simple, short trichomes; lower surface pubescent with simple, short trichomes; venation actinodromous, basal veins 5, secondary veins 5-7 per side. Stipels absent. Inflorescences spiciform, androgynous, axillary, to 3 cm long, mostly female with short male segment; peduncle to 5 mm long, it and rachis pubescent with simple, short trichomes. Female segment to 2 cm long; bracts 2-5, sessile, enlarging in fruit to 8 × 10 mm, reniform, pubescent with short, simple trichomes and short glandular trichomes; margin dentate, teeth c. 15, triangular, central tooth prominent; bracteoles absent. Male segment persistent, to 1 cm long; flowers glomerate; bracts to 0.5 mm long, triangular-lanceolate, ciliate with simple, short trichomes, and two simple, long trichomes to 0.7 mm long at apex. Male flowers: pedicel to 0.5 mm long, sparsely hairy; buds to 0.5 mm diameter, glabrous, papillose. Female flowers 2-(3) per bract, sessile; sepals 3, to 0.5 mm long, triangular, ciliate with simple, short trichomes, margin with sessile glands; ovary c. 1 mm diameter, 3-lobed, smooth, surface hispid with simple, short, erect trichomes; styles 3, to 4 mm long, distinct, sparsely hairy, each divided into 4-5 segments. Allomorphic flowers sometimes present at inflorescence apex, pedicel filiform, to 9 mm long, sparsely hairy; sepals 3, similar to those of normal flowers; ovary 1-lobed, to 3 × 2 mm, hispid with hyaline trichomes to 1 mm long, simple, short trichomes, and some glandular trichomes, distally fimbriate; style 1, to 2 mm long, sparsely hairy. Capsules to 3 mm diameter, smooth, surface pubescent with short simple trichomes and short glandular trichomes. Seeds c. 1 × 0.7 mm, pyriform, foveolate.

NOTE

Acalypha bailloniana was first reduced to a subspecies of A. indica by Hutchinson (1912), and this treatment was followed in subsequent floristic works. Radcliffe-Smith (1987, 1996) treated A. bailloniana as a synonym of A. indica . We consider A. bailloniana to be a distinct species that can be distinguished from A. indica by its dentate bracts with a prominent central tooth and with glandular hairs (vs A. indica with subentire bracts without a prominent central tooth, and with eglandular hairs).

Figures

FIG. 24. — Mature female bracts:A, Acalypha andringitrensis Leandri (H. Perrier de la Bâthie 13640); B, A. ankaranensis I.Montero & Cardiel (A. J. M. Leeuwenberg 14374); C, A. bailloniana Müll.Arg. (G. Viscardi 439); D, A. boinensis Leandri (R. Ramananjanahary 115); E, A. burmanii I.Montero & Cardiel (P. Commerson s.n.); F, A. cardielii I.Montero & G.A.Levin (J. Leandri 115); G, A. chibomboa Baill. (F. Barthelat 1436); H, A. claoxyloides Hutch. (F. Friedmann 5633). Illustration by Iris Montero Muñoz. Scale bars: A, 2 mm; B-H, 1 mm.

FIG. 17. — Distribution map of Acalypha bailloniana Müll.Arg. in Comoros Archipelago.