Acalypha burmanii 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 : 425-426

8. Acalypha burmanii I.Montero & Cardiel

PhytoKeys 108: 93 ( Montero Muñoz et al. 2018a).

Tragia filiformis Poir., Encyclopédie méthodique. Botanique. Paris 7: 727 ( Poiret 1806). — Acalypha acuminata Vahl ex. Baill., Adansonia, Recueil d’observations botaniques 1: 267 ( Baillon 1861) nom. illeg., non A. acuminata Benth. ( Bentham 1854) . — Type: Madagascar?: s.l., s.d., P. Commerson ? s.n. (holo-, P-LAM [P00367371]). ICONOGRAPHY. — Baillon (1891: pl. 188.); Fig. 24E.

ETYMOLOGY. — The epithet honors Dutch botanist Nicolaus Laurens Burman (1743-1793).

DISTRIBUTION AND HABITAT. — Endemic to Madagascar, probably from northeast Madagascar (Fénérive, Toamasina Province). Littoral forest. On sandstone. Altitudinal range unknown ( Fig. 21 ).

PRELIMINARY CONSERVATION ASSESSMENT. — Acalypha burmanii is known from two collections, one collected in 1771 by P. Commerson without locality but probably from northeastern Madagascar, and the other collected in Fénérive by d’Alleizette in 1906. It occurs in littoral forests, which are the most threatened vegetation zone in Madagascar ( Bollen & Donati 2006; Andriamandimbiarisoa et al. 2015). Although data are too limited to estimate its EOO and AOO, Acalypha burmanii is assigned a preliminary conservation status of Critically Endangered, CR B2ab(ii,iii) (probably EX).

MATERIAL EXAMINED. — 2 collections. Madagascar. Commerson, P. s.n. (G[G00324451], P[P04779529, P00324459, P00324460, P00799456], P-LAM[P00367371]); d’Alleizette, Ch. s.n. (L[L0242529]).

REFERENCES. — Müller Argoviensis (1865: 40) as A. spiciflora Burm.f. ; Müller Argoviensis (1866: 867) as A. spiciflora ; Baillon (1891: tab. 188) as A. acuminata ; Baillon (1892: 1004) as A. acuminata ; Heckel (1903: 198) as A. acuminata ; Palacký (1907: 24) as A. acuminata ; Pax & Hoffmann (1924: 137) as A. spiciflora ; Leandri (1942: 269) as A. spiciflora ; Montero Muñoz et al. (2018a: 93).

DESCRIPTION

Shrubs, probably deciduous, height unknown, monoecious. Branches subglabrous, with sparse, simple, short trichomes. Axillary buds subspherical, to 1 × 1.2 mm, perulate, perules 2, imbricate, chartaceous, light brown, glabrous. Stipules to 4 mm long, linear-lanceolate, margin ciliate and with some sessile glands. Petioles 0.5-1 cm long, indumentum similar to that on branches. Leaf blades 2.5-5.5 × 1.8-3 cm, elliptic to elliptic-lanceolate, membranous; base rounded to acute; apex acuminate, acumen to 12 mm long, rounded; margin crenate-serrate, teeth rounded; upper surface glabrous; lower surface subglabrous, with simple, short trichomes on veins; margins ciliate in sinuses; venation actinodromous, basal veins 3, secondary veins 3-4 per side. Stipels glandular, to 0.3 mm long, glabrous. Inflorescences spiciform, androgynous, axillary, to 7 cm long, mostly male with short female segment; peduncle filiform, to 15 mm long, it and rachis subglabrous, with some sparse, simple, short trichomes. Female segment to 2 cm long; bracts 1-2, sessile, enlarging in fruit to 10 × 11 mm, subelliptic, almost glabrous, with some sparse, simple trichomes; margin subentire, slightly discolored; bracteoles absent. Male segment persistent, to 4 cm long; flowers glomerate; bracts to 0.5 mm long, triangular, sparsely hairy. Male flowers: pedicel to 0.7 mm long, sparsely hairy; buds not seen. Female flowers 2 per bract, sessile; sepals 3, to 1 mm long, triangular, sparsely hairy with simple, short, arachnoid trichomes; ovary c. 1 mm diameter, 3-lobed, papillose, surface puberulent with simple, short trichomes; styles 3, to 3 mm long, connate at thickened base, sparsely hairy on rachis, each divided into c. 14 segments. Allomorphic flowers not seen. Capsules to 6 mm diameter, papillose, papillae to 1 mm long, surface sparsely hairy with simple, short, curved trichomes. Seeds c. 3 × 2 mm, pyriform, minutely foveolate.

NOTES

We propose Acalypha burmanii as a new name for Tragia filiformis Poir. ( Montero Muñoz et al. 2018a) because combining T. filiformis under Acalypha is blocked by A. filiformis Poir. ; nor could we use the illegitimate name A. acuminata Baill. See also comments under the excluded species A. spiciflora .

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. 21. — Distribution map of Acalypha burmanii I.Montero & Cardiel in Madagascar.