Argyreia involucrata C.B.Clarke

P. R., Lawand & Shimpale, V. B., 2024, Revision of the genus Argyreia (Convolvulaceae) from India, Rheedea 34 (5), pp. 337-396 : 365-366

17. Argyreia involucrata C.B.Clarke in Hook.f., Fl. Brit. India 4(10): 187. 1883. Lectotype

[designated by Lawand & Shimpale, 2017]:

Maharashtra, Bombay, s.d., N.A. Dalzell 23 (K

[K001081780 digital image!]). Fig. 7a–d

A shrubby twiner, grows up to height of 10–20 ft.; older stems semi-woody, terete, younger stems herbaceous, green–purplish tinged, appressed white strigose, twines around a solid support. Leaf lamina ovate to lance-ovate, 10–15 × 4–8 cm in length, base rounded or sometimes cordate, lobes rounded, apex acute, secondary veins 6–8 pairs, bifurcating towards apex, purple in color, raised beneath, nearly glabrous or very sparsely hairy below; petioles 3–7 cm long, white hairy; Inflorescence a few flowered axillary cymes; peduncles 2–6 cm long, usually equal to or longer than petiole, terete, hairy like stem. Flower sessile, bracteate. Bracts 2, narrowly oblong or lance-ovate, 1–3 cm long, parallel nerved, apex acute, white hairy outer, glabrous inner. Sepals unequal, outer two long 1–1.5 cm long, inner three short 0.7–1 cm long, white hairy outer except on overlapped part, apex acute to narrowly acute. Corolla infundibuliform, 4–6 cm long and 4–6 cm across, pilose on midpetaline band; corolla lobes apiculate; tube dark purple in color. Stamens 5, unequal in length; filaments white 3–3.5 cm long, dilated and glandular hairy at base; anthers pale pink. Ovary off white; stigma biglobose, white. Berries 1–1.5 cm across, yellow.

Flowering & Fruiting: Flowering from August to September and fruiting from October to December.

Habitat: Found in the semi-evergreen to evergreen forests.

Distribution: India (Karnataka, Maharashtra and Tamil Nadu); endemic to peninsular India. As observed during herbarium consultation of present work, the occurrence of species from Andhra Pradesh, Bihar and Chhattisgarh is uncertain, as it is often confused with Argyreia daltonii C.B. Clarke.

Etymology: The specific epithet ‘ involucrata’ refers to the involucrate inflorescence.

Specimens examined: INDIA, Andhra Pradesh, Srikakulum District, Palkonda Hills , s.d., V . Narayanswami 163 ( CAL) . Bihar, Chamaparan District, Bhainsalaton , 18.09.1965, S . P . Banerjee 632 ( CAL); Champaran District, Govardha Forest , 14.11.1963, Br. Shetty 278 ( CAL) . Chhattisgarh, Bastar District, Jagdalpur, Kurandi , October 2007, A . N . Singh 72435 ( BSA) . Goa, South Goa, Marmagao , October 1892, F . Santapau 22738 ( BLAT); Mollem National Park, Molem-Surla Road , 07.02.2002, Mandar Datar 186216 ( BSI) ;

Choramdeu, 26.09.1970, N. P . Singh 186216 (BSI);

South Goa District, Butpal , 10.10.1964, R. S .

Raghavan 103475 (BSI); North Goa District, Betim

Hills, 11.11.1963, S. R. Rolla 92960 ( BSI); South

Goa District, Marmagao, s.d., T. Cooke s.n. (BSI).

Karnataka, North Kannada, Karwar , October 1999, Hallberg & McCann 34818 ( BLAT); North

Kannada, Karwar, 29.07.1956, Z. J. Kapadia 2151

(BLAT); Bagalkot District , Yadahalli, 04.09.1978 ,

R.K. Kochhar 152579 (BSI); Mookambika WLS,

Mavinkatte Forest , 14.10.2008, P . Diwakar & R. K .

Singh 129297 (BSI); Shimoga District, Hulical

Ghat, 16.10.1964, R. S . Raghavan 90462 (BSI);

North Kannada District, Castle Rock, 29.10.1902,

G.A. Gammie 15773 (BSI); Shimoga District, near

Tirthahalli, 26.10.2018, P. R . Lawand 046 (NCK).

Maharashtra, Pune District, Near Wad, October 1891, T. Cooke s.n. ( BSI); Sindhudurg District ,

Kudal, 20.11.1965, B. G . Kulkarni 107646 (BSI);

Raigad District , Raigad Fort, 19.02.1955, V .D.

Vartak 463 (AHMA); Kolhapur District, Ajara,

Pargad, 31.12.2017, P. R . Lawand 015 (NCK),

Kolhapur District, on the way to Patgaon,

September 2016, P. R . Lawand 045 ( NCK). Tamil Nadu, Madras, Travancore , September 1884, J. S . Gamble 14800 (CAL).

Conservation status: The populations are fragmented and area of occupancy (AOO) is less than 2000 km 2. The number of mature individuals within localities are fluctuating and are observed less than 250. Hence the IUCN category Vulnerable (VU, B2c and C2ai) can be assigned to the taxon ( IUCN, 2024).

Notes: The species is closely similar to Argyreia boseana Santapau & Patel in its bract and flower shape. However, it differs from the former in its growing habit (a moderate height twiner), narrow ovate leaves, white indumentum on the leaves, shorter peduncle relative to petiole and fewer flowers in the inflorescence.

Figures

Fig. 7. Argyreia invOluCarata C.B. Clarke (a-d): a. Flowering twig; b. Leaf abaxial surface; c. Inflorescence; d. Sepals. Argyreia kleiniana (Roem. & Schult.) Raizada (e-h): e. Flowering twig; f. Leaf abaxial surface; g. Bracts; h. Sepals. Argyreia lawii C.B. Clarke (i-l): i. Flowering twig; j. Inflorescence; k. Bracts;l. Sepals.