Acalypha claoxyloides Hutch.

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 : 429-430

11. Acalypha claoxyloides Hutch.

Bulletin of Miscellaneous Information, Royal Gardens, Kew 1918: 205 ( Hutchinson 1918). — Type: Seychelles. Astove, Cosmoledo and Aldabra, IV.1907, H. P. Thomasset 243 (lecto-, designated by Montero Muñoz et al. [2018a: 94]: K[K000186504]).

Acalypha fryeri Hutch. , Bulletin of Miscellaneous Information , Royal Gardens, Kew 1918: 206 ( Hutchinson 1918). — Type: Seychelles. Aldabra, s.d., J. Fryer 92 (lecto-, designated here, or possibly holotype: K[K000186506]).

Acalypha aldabrica Pax & K.Hoffm., Das Pflanzenreich (Engler) 147, 16 (Heft 85): 136 ( Pax & Hoffmann 1924). — Type: Seychelles. Aldabra, s.d., W. L. Abbott s.n. (holo-, B?, presumably destroyed; lecto-, designated by Montero Muñoz et al. [2018a: 94]: P[P00887488]; isolecto-, P[P00887489]).

ICONOGRAPHY. — Fig. 24H.

ETYMOLOGY. — The epithet refers to Claoxylon A.Juss. ( Euphorbiaceae ), the genus to which the type specimen was first assigned by Baker.

DISTRIBUTION AND HABITAT. — Endemic to Seychelles (Aldabra group). Mixed xeric scrub on coral limestone, at sea level ( Fig. 25 ). PRELIMINARY CONSERVATION ASSESSMENT. — Acalypha claoxyloides is known from the Aldabra Group Islands (Seychelles). Its EOO is estimated to be 5 233 km 2, close to the threshold of the B1 subcriterion of the Vulnerable category, and its AOO 52 km 2, which is less than the 500 km 2 threshold of the B2 subcriterion of the Endangered category. The ecosystems in the Aldabra atoll are remarkably intact and it has been a UNESCO World Heritage Site since 1982, but on the other atolls the forests have been seriously degraded by conversion to plantations, mainly coconut, and by guano extraction. Currently the main threat is alien species ( Roberts 1988; Safford 2013; Baret et al. 2013). Acalypha claoxyloides seems to be a very common shrub on the atolls of this group of islands, and it meets the EOO values needed for a threatened category, but the number of locations is too high to meet the conditions required for a listing under the Endangered category;, it therefore could be assessed as Near Threatened (NT) under criterion B. However, ongoing habitat loss on some atolls and the presence of alien species will likely cause continued decline of its EOO and AOO in the near future, so we assess this species as Endangered under subcriteria B1 and B2. MATERIAL EXAMINED. — 35 collections. Seychelles. Abbott, W.L. s.n. (P[P00887488, P00887489]); Fitzgerald, D.V. 5989 (BR[BR0000014624568]), 6017 (BR[BR0000014624575], P[P04779371]); Fosberg, F.R. 48741 (MO[MO-2965769]), 48742 (MO[MO-2965771], NY[NY 03091181], US[US01287312]), 48771 (M[MO-2965756], NY[NY3091176], [US01287313]), 48900 (MO[MO-2965770], NY[NY3091177], US[US01287308]), 49065 (MO[MO-2965773], NY[NY3091179], US[US01287316]), 49627 (US[US01287309]), 49661 (GH[GH01097234], MO[MO-2965772], NY[NY3091178]), 49662 (MO[MO-2965768], NY3091180, US01287315), 49730 (US01287304), 49804 (US01287307); Frazier, J. 3 (US01287328), 29 (K), 602 (US01287306); Friedmann, F. 5633 (P[P00870926, P00870927]), 5634 (P[P00870925]); Fryer, J.C.F. 18 (K[K000186505]), 92 (K[K000186506]); Gardiner, J.S. 18 (K); Gwynne 1240 (K); Merton 7010 (K); Renvoize, S. A. 748 (BR[BR0000014624629], L[L0241259, L0241260]), 768 (L[L0241258], P[P05481893]), 1001 (BR[BR0000014624605], L[L0241257], P[P05481872]), 1288 (BR[BR0000014624582], L[L0241255, L0241256]), 1289 (BR[BR0000014624599], L[L0241253, L0241254], P[P05481871]), 1314 (K); Rhyne, C. 863 (US[US01287317]); Ridgway, T. 111 (US[US01287305]); Stoddart, D.R. 748 (K), 998 (K), 1231 (K); Thomasset, H.P. 243 (K[K000186504]).

REFERENCES. — Hemsley (1919: 130); Hemsley (1919: 131) as A. fryeri ; Pax & Hoffmann (1924: 136) as A. aldabrica ; Fosberg (1974: 263); Renvoize (1975: 152); Robertson (1989: 199); Govaerts et al. (2000: 56); Sagun et al. (2006: 124); Montero Muñoz et al. (2018a: 94).

DESCRIPTION

Small trees, deciduous, to 3 m tall, monoecious. Branches reddish, subglabrous, with some simple, arachnoid trichomes, greyish, with thick nodes, and glabrescent when mature. Axillary buds spherical, to 1.5 mm diameter, perulate, perules 2, valvate, membranous, light brown, woolly with simple, arachnoid trichomes. Stipules to 1.5 mm long, triangular-lanceolate, pubescent with simple, arachnoid trichomes. Petioles 2-3 cm long, indumentum similar to that on young branches. Leaf blades (5-)6-11(-14) × (3-) 4-8 cm, ovate-lanceolate to elliptic-lanceolate, chartaceous; base rounded to acute; apex acuminate, acumen to 5 mm long, obtuse; margin crenate, slightly revolute, teeth rounded; upper and lower surfaces subglabrous, with some simple, arachnoid trichomes on veins, lower surface also with flattened resinous glands; venation pinnate, secondary veins to 8 per side. Stipels glandular, to 0.5 mm long, glabrous. Inflorescences spiciform, androgynous and male, axillary. Androgynous inflorescences to 5.5 cm long, mostly male with short female segment; peduncle to 30 mm long, it and rachis laxly pubescent with simple, arachnoid trichomes. Female segment to 2 cm long; bracts 1-2, sessile, enlarging in fruit to 10-19 mm, reniform, subglabrous, appressed-pubescent at base, and with flattened resinous glands, margin denticulate, teeth 19-23, triangular, sometimes ending in sessile gland, central tooth not prominent; bracteoles sessile glands, glabrous. Male segment deciduous, to 3cm long; flowers glomerate,with stalked, flattened resinous glands between pedicels; bracts to 1 mm long, ovate-lanceolate, sparsely hairy with simple, arachnoid trichomes. Male inflorescences to 4 cm long; subsessile,peduncle to 3 mm long, it and rachis appressed-pubescent with simple, short trichomes; flowers glomerate; bracts similar to those on the male segment in androgynous inflorescences. Male flowers: pedicel to 2 mm long, sparsely hairy; buds to 1 mm diameter, sparsely hairy. Female flowers 2 per bract, sessile; sepals 3, to 1 mm long, ovate-triangular, woolly with simple, arachnoid trichomes; ovary c. 1 mm diameter, 3-lobed, smooth, surface woolly with simple, arachnoid trichomes, and with flattened resinous glands; styles 3, to 5 mm long, distinct, sparsely hairy on rachis with simple, arachnoid trichomes, each divided into c. 10 segments. Allomorphic flowers not seen. Capsules to 3.5 mm diameter, smooth, surface appressed-pubescent with simple, short, trichomes and flattened resinous glands. Seeds c. 1.3 × 1 mm, pyriform, foveolate.

NOTE

1) Hutchinson did not indicate the herbarium where the holotype is located, so the single specimen found is designated as the lectotype; and 2) Acalypha claoxyloides is widespread in the Seychelles archipelago. It is very closely related to A. pubiflora (Klotzsch) Baill. , known from southeastern Africa ( Botswana, Malawi, Mozambique, South Africa and Zimbabwe), of which it may be a synonym. More study of the African material, as well as the Australian material treated as A. pubiflora var. australica Radcl. -Sm. ( Radcliffe-Smith 1990, 1996), is needed to unravel the A. pubiflora Baill. complex.

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. 25. — Distribution map of Acalypha claoxyloides Hutch. in Seychelles (Aldabra group).