Mezoneuron cucullatum (Roxburgh) Wight & Arnott

Clark, Ruth P., 2016, A Taxonomic Revision of Mezoneuron (Leguminosae: Caesalpinioideae: Caesalpinieae), Phytotaxa 274 (1), pp. 448-450 : 448-450

5. Mezoneuron cucullatum (Roxburgh) Wight & Arnott

Prod. Fl. Penins. Ind. Or. 1: 283 (1834).

Type:— INDIA: “A native of the Delta of the Ganges where it was found by Dr William Carey, and by him introduced into the Botanic Garden at Calcutta where it blossoms in February and March”. (Voigt, J.O. 1845). No specimen matching this description was found at CAL.

“Au BM, un spécimen Roxburgh s.n. pourrait être considéré comme type ” (Vidal & Thol 1976). A specimen of Caesalpinia cucullata Roxb., Roxburgh s.n. at BM (BM000958800) has been annotated as the type by Vidal, Jul. 1974.

Lectotype (here designated):— India Orientalis, Roxburgh s.n., BM (BM000958800!)

Epitype (here designated):— Wallich cat. n. 5828E (2 sheets), K (K000264194!, K000264195!)

Basionym. Caesalpinia cucullata Roxb. ex Roxb. Flora Indica 2: 538. 1832; Hort. Bengal: 32. 1814. nom. nud., as C. cuculata Roxb.

Synonym. Mezoneuron macrophyllum Blume ex Miq. Fl. Bat. 1 (1): 104. 1855.

Type:— JAVA: Batav 2100. Holotype L (L0018781!); isotypes L (L0018780!, L0018782!).

Synonym. Mezoneuron cucullatum (Roxb.) Wight & Arn. var. grandis Heyne ex Baker in Hook f., Fl. Br. Ind. 2: 258. 1878 ( Caesalpinia grandis Heyne ex Wall., Cat. n. 5830B).

Type:— INDIA: Madras, Wallich cat. n. 5830B, K (K000264186!).

Synonym. Mezoneuron cucullatum (Roxb.) Wight & Arn. var. robustum Craib. Fl. Siam. Enum. 1: 499. 1928.

Type :— THAILAND: Wangkia, Kanburi [Rachaburi], 9.2.1926, Kerr 10479, K (K000264158!) .

Robust woody climber or scandent shrub to 20 m in length. Stems with scattered recurved prickles, older stems with spine-tipped tubercles, glabrous. Stipules caducous, triangular or oblong, 1 × 1–2 mm, glabrous. Leaves with (2–) 3–6 [–7] pairs pinnae; 2–5 pairs leaflets per pinna; petiole 6.5–13 cm; leaf rhachis (10–) 16–45 (–55) cm, with paired recurved prickles at the pinna insertion points, and scattered on the internodes, prickles also on petiole; pinnae 6–21 cm; sometimes with recurved prickles at the leaflet insertion points and scattered on the internodes; leaf rhachis, petiole, and pinna rhachis glabrous. Leaflets opposite or subopposite; the terminal leaflets elliptic to slightly ovate or obovate, base symmetric or oblique, apex acuminate, slightly rounded, mucronulate, 4–14.5 ×

A TAXONOMIC REVISION OF MEZONEURON

Phytotaxa 274 (1) © 2016 Magnolia Press • 13 2.2–6.5 cm; lateral leaflets elliptic to ovate, base symmetric to oblique, apex acuminate, slightly rounded, mucronulate, (3–) 3.8–15.7 × 2.3–6.2 cm; all leaflets glabrous on both surfaces, upper surface glossy; 2˚ venation anastomosing, 3˚ venation reticulate, veins raised and clearly visible on both surfaces. Inflorescence a raceme or panicle, axillary or terminal, to 65 cm, axes and pedicels sometimes with scattered recurved prickles; usually glabrous, but sometimes (very) sparsely short orange or golden tomentose; pedicels (4–) 7–17 mm, articulated 2–5 mm below the hypanthium, glabrous or very sparsely orange tomentose. Bracts sometimes present, caducous, triangular, semicircular or oblong, 1 × 2–3 mm, glabrous; bracteoles caducous, 2–4 mm, narrowly lanceolate, glabrous or with few hairs. Flowers with a hypanthium 2–5 × 6–12 mm; lower calyx lobe 6–16 × 4–8 mm, other calyx lobes 4–10 × (3–) 4–6 mm; hypanthium and calyx usually glabrous, sometimes (very) sparsely orange tomentose on outer surface. Median petal broad, bilobed to half of length, 7–10 × 12–17 mm, entirely glabrous, or ciliate on margins of basal portion. Upper lateral petals suborbicular, 6–12 × 5–8 mm, including claw ca. 1 mm long, moderately orange tomentose on inner surface of basal portion of blade, sometimes only on margins. Lower lateral petals elliptic to slightly obovate, apex rounded to truncate, 8–15 × (4–) 5–7 mm, including claw ca. 1 mm long, moderately orange tomentose on inner surface of basal portion of blade, sometimes only on margins. Stamen filaments strongly exserted, flattened, 12–33 mm long, sparsely orange tomentose on the basal ½ on inner surface. Ovary 5–12 mm long, style 15–32 mm long, both glabrous; stigma truncate, oblique, ca. 0.5 mm diameter, glabrous. Fruit chartaceous; elliptic, the base oblique, apex rounded, or wing extending to form a curved beak; 7–14.5 (–17) × 1.7–4.4 (–5.2) cm, including stipe ca. 4–5 mm, and wing 4–10 mm wide; fruit surface glabrous; venation reticulate, raised and visible on fruit body, anastomosing and slightly visible on the wing; hypanthium persistent. Seeds 1 (rarely 2) per fruit; positioned centrally in fruit, generally visible in outline on fruit exterior when mature; flattened, orbicular, ca. 1 cm diameter, glossy, brown.

Distribution:— China, Nepal, Myanmar, India, Thailand, Laos, Vietnam, Java, Borneo. ( Fig 6).

Habitat and ecology:—In evergreen or mixed evergreen-deciduous forest, forest fringes and scrub, stream margins, on limestone or granite. Elevation to 1800 m. Seems to prefer a strong seasonal drought, although is also known from regions without a dry season (Borneo).

Phenology:— China: flowering July–February, fruiting March–October. India, Myanmar, Bhutan: flowering October–July, fruiting January–May. Nepal: flowering September–December, fruiting November–February. Thailand, Laos, Vietnam: flowering January–February, fruiting November–March. Malesia: flowering April–October, fruiting time unknown.

14 • Phytotaxa 274 (1) © 2016 Magnolia Press

CLARK

Preliminary conservation assessment:—Extent of Occurrence 10,973,076.606 km 2 = LC; Area of Occupancy 212.000 km 2 = EN.

Category assigned:—Least Concern (LC).

Taxonomic Notes:—The lectotype was selected on the basis of being a Roxburgh specimen that has been previously indicated by Vidal and Thol (1976) as a type, and annotated as such by Vidal, and that no more suitable collections have been found amongst the specimens studied. The leaf of this specimen is incomplete, however, and an epitype with a more complete and representative leaf is thus also here designated. The epitype also bears fruit, which is described in the protologue, but lacking on the lectotype.