Acalypha lamiana (Leandri) 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 : 448-451

24. Acalypha lamiana (Leandri) I.Montero & Cardiel

PhytoKeys 108: 101 ( Montero Muñoz et al. 2018a). — Acalypha reticulata var. urophylla f. lamiana Leandri, Notulae Systematicae. Herbier du Muséum de Paris. Phanérogramie. Paris 10: 263 ( Leandri 1942). — Type: Madagascar. Prov. Mahajanga, Réserve de Marohogo, 28.XII.1938, H. J. Lam & A. D. J. Meeuse 6127 (lecto-, designated by Montero Muñoz et al. [2018a: 102]: P[P05604417]; isolecto-, L[L0242109]). — Former syntypes: Madagascar. Prov. Antananarivo, Tsarasaotra, II.1898, H. Perrier de la Bâthie 457 (P [P05604408, P05604409, P05604410, P05604413]); Prov. Fianarantsoa, Ankirihitra près du mont Tsiltondroina, III.1902, H. Perrier de la Bâthie 9817 (P[P05604403]), 9817 bis (P[P05604404, P05604405]); Prov. Mahajanga, NW of Ankazobe, Vallée de l’Ikopa, 14.III.1930, R. Decary 7535 (P[P05604421]); Massif de l’Ankarafantsika, 11.I.1938, R. Decary 12876 (P[P05604420]); Bekodoka, 17.IX.1930, R. Decary 8109 (P[P05604422]); Région d’Antsalova, 1932-1933, J. Leandri 998 (P[P05604411]); Tsingy du Bemaraha, 3-6.X.1932, J. Leandri 176 (P[P05604415]); Dokolahy, II-IV.1933, J. Leandri 602 (P[P05604414]); Prov. Toliara, Soahazo Forest, 100 m, 22.X.1932, J. Leandri 414 (P[P05604416]).

ICONOGRAPHY. — Leandri (1942: 263); Figs 41 ; 46D.

ETYMOLOGY. — The epithet honors Dutch botanist Herman Johannes Lam (1892-1977).

DISTRIBUTION AND HABITAT. — Endemic to Madagascar (Boeny, Melaky, Bongolava, Menabe, Atsimo-Andrefana, and Anosy). Dry deciduous forest, secondary grasslands, and pastures (savanna). Frequently on Mesozoic limestone. Altitudinal range (25-) 100-800 (-1200) m ( Fig. 42 ).

PRELIMINARY CONSERVATION ASSESSMENT. — The EOO of Acalypha lamiana is estimated to be 376 831 km 2 and its AOO 120 km 2, which is less than the 500 km 2 threshold of the B2 subcriterion of the Endangered category. This species grows mainly in the western dry deciduous forests (see comments in A. diminuta ). It has been collected in some protected areas, but it is also known from several unprotected forests subject to various threats (uncontrolled fires for grazing and crops, logging, mining, etc.). Ongoing habitat loss will cause continued decline of its EOO and AOO. Acalypha lamiana is assessed as Near Threatened (NT) under criterion B. It meets the AOO 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.

MATERIAL EXAMINED. — 50 collections. Madagascar. Afzelius, K. 81 (P[P00508497]); Baron, R. 6808 (K); Boivin, L.H. s.n. (K[K000186503]); Bolliger, R.F. RFB 083 (G[G00340310]); Capuron, R. 1935 (P[P04804747]), 1953 (P[P04779856, P04779858, P04779859]); Decary, R. 8109 (P[P05604422]), 8161 (K, P[P00324533]), 12876 (P[P05604420]), 15198 (P[P00508466]), 15725 (G, MA, P[P05547224]), 17069 (P[P05510110, P00324526]); Gillespie, L. 4141 (K, MO, P[P00513154], US[US01287449]), 10691 ( MO), 10701 ( CAN), 10702 ( CAN), 10703 ( CAN), 10832 ( CAN); Harmelin 10247 (P[P04804764]); Humbert , H. 5102 (P[P04779863]), 12638 (P[P00508441, P00508442]), 12644 (P[P04804526, P04804527]), 19738 (P[P00508432]), 19990 (P[P00508431]), 20005 (P[P04779862]); Lam, H.J. 6127 (L[L0242109], P[P05604417]), bis 27 (P[P05604418]); Leandri, J. 176 (P[P05604415]), 414 (P[P05604416], US[US01287453]), 602 (P[P05604414]), 998 (P[P05604411]), 2060 (P[P04804746]), 2652 (P[P05543667, P00324505]), 2711 (G, K, P[P04804745]), 2856 (G, K, MO[MO-2965757], P[P04779857]), 2921 (P[P04779855]), 3018 (P[P04804744]), 4252 (P[P04804750]), s.n. (P[P05604419]); Nicoll, M.F. 377 (K, MO, P[P05604412]); Nusbaumer, L. LN 875 (K), LN 3084 ( BR [BR0000015215604V], G[G00376211], MO[MO-2965725]); Perrier de la Bâthie, H. 457 (P[P05604408, P05604409, P05604410, P05604413]), 9817 (P[P05604403]), 9817 bis (P[P05604404, P05604405]); Rakotomalaza, P.J. 280 (P[P05516018]); Rakotovao, C. 4638 (P[P04804767]), 6237 (G, MO[MO-2965731], TAN); Ravelonarivo, D. 4528 ( MO); Thunberg s.n. (S[S17-37572]).

REFERENCES. — Montero Muñoz et al. (2018a: 101).

DESCRIPTION

Shrubs, probably deciduous, to 3 m tall, monoecious. Branches laxly pubescent with curved, antrorse trichomes, glabrous when mature. Axillary buds ovoid, to 1 × 0.5 mm, perulate, perules 2, valvate, membranous, blackish, glabrous. Stipules to 6 mm long, triangular, subglabrous, with some hyaline trichomes to 1 mm long, margin papillate. Petioles filiform, 1-2.5(-4) cm long, indumentum similar to that on young branches. Leaf blades 5-7 × 2-2.5(-3.5) cm, ovate-lanceolate to elliptic-lanceolate, membranous; base rounded to obtuse, rarely subcuneate; apex acuminate, acumen to 10 mm long, acute; margin serrulate, reddish, teeth minute, sometimes with simple trichome at apex; upper surface subglabrous, with some simple, appressed trichomes at base of midrib; lower surface subglabrous, with some sparse, simple trichomes; margins sparsely ciliate; venation actinodromous, basal veins 3, secondary veins 4-5 per side. Stipels glandular, to 0.5 mm diameter, glabrous. Inflorescences spiciform, androgynous, and solitary female bracts, axillary. Androgynous inflorescences to 4 cm long, mostly male with short female segment; sessile, rachis filiform, subglabrous, with some curved trichomes at base. Female segment: bracts 1-(4), sessile, enlarging in fruit to 7 × 6 mm, subrounded, glabrous; margin slightly crenate-dentate, revolute, reddish, teeth rounded, central tooth sometimes prominent; sterile bracts sometimes present, similar to regular female bracts, to 11 × 9 mm; bracteoles absent. Male segment persistent, to 3 cm long; flowers glomerate; bracts to 0.3 mm long, triangular, sparsely hairy. Solitary female bracts sessile, similar to those on androgynous inflorescences. Male flowers: pedicel to 0.5 mm long, sparsely hairy; buds to 0.7 mm diameter, glabrous. Female flowers 1 per bract, sessile; sepals 3, to 0.5 mm long, triangular, glabrous; ovary c. 1 mm diameter, 3-lobed, papillose-hispid, papillae on middle of each carpel, ending in simple trichome to 0.6 mm long, surface glabrous; styles 3, to 3 mm long, distinct, sparsely hairy, each divided into c. 10 segments. Allomorphic flowers sometimes present, axillary; pedicel filiform, to 19 mm long, glabrous; sepals to 0.5 mm long, triangular, glabrous; ovary 1-lobed, to 1.5 mm diameter, densely pubescent, distally fimbriate; style 1, to 4 mm long, glabrous. Capsules to 3 mm diameter, papillose-hispid, papillae similar to that on ovary, surface glabrous. Seeds c. 1.5 × 1.2 mm, pyriform, foveolate.

NOTES

1) Acalypha lamiana was treated by Leandri (1942) as a form of A. reticulata var. urophylla (treated here as A. urophylla ). After studying the type collections, it seems clear to us that A. lamiana must be considered a distinct species ( Montero Muñoz et al. (2018a). Acalypha lamiana differs from A. urophylla mainly by the leaves that are rounded at the base and reddish at the margins, and its subentire, eglandular female bracts vs leaves that are usually rounded to subcordate, sometimes acute, at the base and not reddish at the margins, and dentate female bracts with small sessile glands at the margins in A. urophylla ; 2) one of the former syntypes, H. Perrier de la Bâthie 9817, was wrongly transcribed by Leandri (1942: 263) as “ 8917 ”; and 3) many specimens bear malformed leaves, apparently due to insect damage or galls.

Figures

FIG. 41. — Acalypha lamiana (Leandri) I.Montero & Cardiel:A, flowering branch; B, detail of lower leaf surface;C, detail of node, stipules,and petiole base; D, mature female bract; E, ovary and styles; F, calyx of the female flower; G, capsule; H, seed. Based on L. N. Nusbaumer LN875 (K). Illustration by Laura González Hernández. Scale bars: A, 1 cm; B, D, E, G, H, 1 mm; C, 2 mm; F, 0.5 mm.

FIG. 46. — Mature female bracts: A, Acalypha indica L. (Sagun et al., 2010, Sagun & Risna SR58); B, A. integrifolia Willd. (P. Commerson 655); C, A. isaloensis I.Montero & Cardiel (J.-N. Labat 2119); D, A. lamiana (Leandri) I.Montero & Cardiel (H. J. Lam & A. Meeuse 6727); E, A. lanceolata Willd. var. glandulosa (Müll.Arg.) Radcl.-Sm. (H. Perrier de la Bâthie 9929); F, A. leandrii I.Montero & Cardiel (J. Leandri 2037); G, A. leonii Baill. (L. Gautier LG4003); H, A. lepidopagensis Leandri (H. Perrier de la Bâthie 9726). Illustration by Iris Montero Muñoz. Scale bars: 1 mm.

FIG. 42. — Distribution map of Acalypha lamiana (Leandri) I.Montero & Cardiel in Madagascar.