Aganope agastyamalayana M.B. Viswan., U. Manik. & A.C. Tang., 2003

Viswanathan, Manikandan, U. & Tangavelou, A. C., 2003, A new species of Aganope (Fabaceae) from the Southern Western Ghats, Peninsular India, Adansonia (3) 25 (2), pp. 205-210 : 206-208

Aganope agastyamalayana M.B. Viswan., U. Manik. & A.C. Tang. , sp. nov.

Affinis Aganope thyrsiflora (Benth.) Polhill ramulis, ferruflavido, sericeibus, folioliis 5 rare 3 or 7, dissimilaris, ferruflavido sericeibus, nervis lateralis, 9-15 paribus, petiolis stipulisque ferruflavido sericeibus, bracteis late ovatis ferruflavido sericeibus, filamentis glabribus, stigmatis capitellatibus, legumen tumidus, oblongus, semina tumida, ad basin concava, 24-27 mm longis, 15-18 mm latis, differt.

TYPUS. — Viswanathan & Manikandan 14473, India, Tamil Nadu state, Kalakkad-Mundanthurai Tiger Reserve (eastern slopes of Agastyamalai hills, 8°20’- 8°53’N and 77°10’- 77°35’E), Nondimangadu , c. 1,100 m, 31 May 2001, (holo-, MH; iso-, herbarium of the Sri Paramakalyani Centre for Environmental Sciences) .

Derris brevipes Baker var. travancorensis Thoth., Bull. Bot. Surv. India 6: 67, fig. 2 (1964); Sanjappa in Leg. India: 144 (1992). — Type: T.F. Bourdillon 17409, India, Kerala state, Travancore hills (western slopes of Agastyamalai hills): Velleva mallay, 19 Nov. 1890, ± 2,333 m (MH!).

Climbing shrubs, robust; branchlets obtusely quadrangular when young, terete when mature, striate, lenticellate, densely rusty yellowish sericeous when young, sparsely rusty yellowish sericeous when mature; stems hollow; internodes 3.5-12.5 × 0.4-0.8 cm. Leaves alternate, imparipinnate, 16-34.5 × 20-27 cm, densely rusty yellowish sericeous; stipules oblong-lanceolate, c. 2.5 × 1 mm, caducous, apex acuminate; petioles canaliculate above, grooved beneath, 4.7- 14 × 0.2-0.3 cm; leaflets mostly 5, rarely 3 or 7, dark brown or dark brownish yellow above, pale yellowish brown beneath, unequal, larger towards apex, margin undulate and cartilaginous, apex cuspidate; first pair of laterals elliptic-ovate or elliptic-oblong, 10.7-14.4 × 5.4-6.9 cm, base obtusely rounded or obliquely rounded; second pair of laterals oblong-obovate or oblongoblanceolate, 12-19 × 4.9-7.8 cm, obtusely or acutely rounded; third pair of laterals oblongelliptic, 12.2-12.9 × 4.2-4.5 cm, base acute; terminal ones oblanceolate, oblong-oblanceolate or oblanceolate-oblong, 12.4-22.5 × 4.2-10.4 cm, apex obtusely rounded or acute and cuspidate, margin undulate; stipels 2, linear-oblong, c. 3.8 × 1 mm; midrib canaliculate above, grooved beneath; lateral nerves 9-15 pairs, impressed above, raised beneath, terminated faintly below margin; petiolules brownish yellow, 0.9-1.5 × 0.1-0.3 cm, canaliculate above, grooved beneath. Inflorescence in lax thyrsoid panicles, both axillary and terminal, densely rusty yellowish sericeous on peduncles, pedicels, bracts and bracteoles; peduncles quadrangular; primary panicles 7.5-45 × 5-12.5 cm; secondary ones 3-5 × 1- 1.5 mm; thyrses 10-14, 0.3-2.2 cm apart between, each 3-6-flowered, c. 1.8 × 2.5 cm. Flowers 1.2-1.4 × 0.9-1 cm, zygomorphic; bracts 2, broadly ovate, 1.8-3.2 × 1.2-1.5 mm; bracteoles 2, ovate, 1.5-2 × 0.8-1.2 mm; pedicels brown, 0.8-2.4 × 0.7-1.4 mm. Calyx cup campanulate, 4.6-4.8 × 5-5.2 mm, oblique at one side, densely rusty yellowish sericeous outside, gland dotted inside; rim truncate but faintly 5- toothed. Standard violet and glabrous inside, brown sericeous outside, orbicular, 12-12.5 × 12.5-13 mm, 25-30-nerved, apex emarginate; claw to 1.8 × 2 mm, glabrous outside, finely sericeous inside, not adherent to keels in lower half; callosites absent; wings 2, white, oblong, 12- 12.8 × 3.5-3.9 mm, distinctly clawed to 4 × 1 mm, glabrous inside, sericeous above claw to apex except glabrous on the margin toward the base; keels 2, white, oblong, 11.3-11.5 × 3.3- 3.5 mm, distinctly clawed to 4.7 × 1 mm, glabrous inside, sericeous above claw and in the terminal half. Stamens 10, white with yellowish striations, diadelphous, 9 + 1, at alternate levels, 5 longer, 4 shorter, c. 12 × 8.5 mm, 10 th stamen free to base; bundle 7.6-9.2 × c. 6.9 mm; individual filaments c. 9.2 × 0.9 mm; free portion of filaments c. 0.3 mm in diam., 1.2-1.5 mm long; anthers brown, dithecous, oblong, larger ones c. 1.1 × 0.75 mm, smaller ones c. 0.9 × 0.65 mm, longitudinally dehiscent. Ovary white, linearoblong, sericeous, c. 11.5 × 1.6 mm; ovules 4-6, white, reniform, c. 0.6 × 0.3 mm; style white, arcuate, c. 1.8 × 1 mm, attenuate towards apex, glabrous; stigma pale yellow, capitellate, c. 0.2 × 0.2 mm. Pods flat, oblong, 9.5-14 × 2.5-3.4 cm, narrowly winged on both sutures, reticulately veined, 2-3-seeded, densely rusty yellowish sericeous when young, sparsely rusty yellowish sericeous when mature, arcuate towards apex, dehiscent when dry; wing 2-3.5 mm across; venation reticulate, alternate to seeds. Seeds reddish brown, broadly obloid and flattened, 2.4-2.7 × 1.5-1.8 cm, shiny, base concave, apex convex; hilum eccentric, c. 4 × 3.5 mm; radicle spread, c. 0.7 mm across. — Fig. 1.

PARATYPES. — T.F. Bourdillon 17409, India, Kerala state, Travancore hills (western slopes of Agastyamalai hills): Velleva mallay, 19 Nov. 1890, ± 2,333 m ( MH!); Viswanathan & Manikandan 18278, Tamil Nadu state, Kalakkad-Mundanthurai Tiger Reserve (8°20’- 8°53’N, 77°10’- 77°35’E), Nondimangadu , c. 1,100 m, 21 May 2002 (herbarium of the Sri Paramakalyani Centre for Environmental Sciences) .

D ISTRIBUTION. — Endemic to the Agastyamalai hills [eastern slopes (Kalakkad-Mundanthurai Tiger Reserve in Tamil Nadu state) and western slopes (Travancore hills in Kerala state)], 8°20’- 8°58’N, 77°10’- 77°35’E.

HABITAT AND ECOLOGY. — Southern tropical wet evergreen forest, associated with the following trees: Ardisia pauciflora Heyne ex Roxb. , Elaeocarpus venustus Bedd. , Eugenia rottleriana Wight & Arn. , Euonymus dichotomus Heyne ex Roxb. , Ficus nervosa Heyne ex Roth var. nervosa , Filicium decipiens (Wight & Arn.) Thw. , Isonandra lanceolata Wight , Memecylon subcordatum Cogn. , Polyalthia tirunelveliensis M.B.Viswan. & U. Manik. , Sapindus emarginatus Vahl , Schefflera rostrata (Wight) Harms var. micrantha (Clarke) Mahesh. , Trema orientalis (L.) Blume, shrubs of Alpinia galanga Sw. , Elettaria cardamomum (L.) Maton var. major Thw. , Sarcandra chloranthoides Gard. and Tabernaemontana gamblei Subram. & Henry. Associated herbs include Amorphophallus smithsonianus Sivadas. , Christella parasitica (L.) H. Lév., Elatostema lineolatum Wight var. setosum Henry , Goodyera procera (Ker-Gawl.) Hook. , Impatiens verticillata Wight , Peperomia dindigulensis Miq. , P. tetraphylla (Forst.f.) Hook. & Arn. and climbers such as Cyclea peltata (Lam.) Hook. f. & Thoms. and Piper mullesua Buch. Ham. ex D. Don.

PHENOLOGY. — Flowering in April and May; fruiting in May and June.

CONSERVATION STATUS. — SANJAPPA (1991) accepted rare status assigned by AHMEDULLAH & NAYAR (1986) to Derris brevipes var. travancorensis . MANILAL & RAVEENDRAKUMAR (1998) stated that the taxon is endemic to Kerala state but NAYAR (1996) doubted its continued existence and suggested that it was possibly extinct. GOPALAN & HENRY (2000) likewise assigned it to the extinct category based on a CAMP (Conservation Assessment and Management Plan) analysis. Aganope agastyamalayana is known only from eastern and western slopes of Agastyamalai hills in certain localities. Analysis field data (VISWANATHAN & MANIKANDAN, pers. observ. 2001, 2002), earlier collections and literature, we assign an IUCN Red list Category of CR — Critically Endangered (B2 - Area of occupancy estimated to be less than 10 km 2; a - severely fragmented; b - continuing decline, observed and inferred basing; ii - area of occupancy and iv - number of locations).

Aganope agastyamalayana is so named because it comes from Agastyamalai hills comprising Kalakkad-Mundanthurai Tiger Reserve (eastern slopes) in Tamil Nadu state and Travancore hills in Kerala state (western slopes) in the Southern Western Ghats of India. As the varietal epithet travancorensis does not cover Kalakkad-Mundanthurai Tiger Reserve (eastern slopes) in Tamil Nadu state it is rejected.

NOTES. — The habit of Aganope agastyamalayana was stated as a dwarf shrub by THOTHATHRI (1964) but our observations indicate that it is a robust climbing shrub. The distinguishing characters of A. agastyamalayana and A. thyrsiflora are shown in Table 1 .

Figures

Fig. 1. — Aganope agastyamalayana M.B. Viswan., U. Manik. & A.C. Tang.: A, habit (flowering twig); B, stipule; C, stipel; D, bract; E, bracteole; F, flower; G, calyx; H, standard (dorsal side); I, standard (ventral side); J, wing petals (dorsal view); K, keel petals (dorsal view); L, flower without petals; M, stamens; N, ovary; O, longitudinal section of ovary; P, transverse section of ovary; Q, pod; R, seed (lateral view); S, seed (front view). Viswanathan & Manikandan 14473.