Ceropegia ravikumariana Kambale & Gnanasek., Rheedea

S. S., Kambale & Abstract, S. R. Yadav, 2019, Taxonomic revision of Ceropegia (Apocynaceae: Ceropegieae) in India, Rheedea 29 (1), pp. 1-115 : 13

Ceropegia ravikumariana Kambale & Gnanasek., Rheedea 26(1): 57. 2016. Type: INDIA, Tamil Nadu, Tirunelveli district, Naraikkadu , 08028’ 11.7 ” N, 77029’ 01.5 ” E, 1368 m, 10.09.2010, K. Ravikumar & K. Murugan 110037 (holo MH!; iso FRLH!). Fig. 7

Perennial repent (rarely erect) to twining herbs. Rootstock tuberous; tubers 1.8–3.5 cm diam., globose or horizontally elongated; roots 2.5–9 cm long, fascicled, fleshy. Stem 20–100 cm long, 1–2 mm in diam., terete, nodes 1–6 cm long, usually branched, purple to greenish, glabrous. Lamina 2–3.7 × 0.3–0.6 mm, linear-lanceolate, acute at apex, narrowed at base, ciliolate along margins and midnerve beneath, deep green above, pale below; petioles 2–7 mm long, channeled above, puberulous in young leaves, glabrous otherwise. Inflorescence 2-flowered extra-axillary; peduncles 2–5 mm long, slender, glabrous; bracts 2, 1.2–2 mm long, linear; pedicels 3–8.5 mm long, slender, glabrous. Sepals 2–3.5 mm long, subulate, glabrous. Corolla 9–15 mm long, straight, glabrous, whitish-yellow; tube 5–10 × c. 2 mm, straight or slightly curved, much dilated at base, with downwardly pointed trichomes within, trichomes absent at the base, striated with purple lines; lobes 5, ovate-lanceolate, 2.5–6 × c. 2.8 mm, connate at the tip forming sub-globose cage, slightly reflexed along the margin, glabrous exterior, hairy within with downwardly pointed hairs, yellowish. Corona bi-seriate, 4–4.5 mm long; outer of 5 triangular to undulate lobes, saucer-shaped, slightly reflexed and hairy along margins and within, yellow margined with purple; inner of 5 linear lobes, c. 1.4–3 mm long, erect, spathulate, opposite to outer corona, yellow. Pollinarium c. 0.2 × 0.4 mm. Follicles in pairs, usually unequal, rarely equal, 8–8.5 cm long, straight, erect, tapering at both ends, blunt at tips, glabrous. Seeds 6.5–7 × 1.5– 2 mm, narrowly elliptic, brown; wings yellowish, comose; coma 1.8–2.8 cm long, silky white.

Flowering & fruiting: September–March.

Distribution: Endemic to Tamil Nadu, India.

Specimens examined: INDIA, Tamil Nadu, Naraikkadu (grown in garden), 30.07.2014, S. S . Kambale & K . Ravikumar SSK 254; Ibid. , 08.08.2014, S. S . Kambale & K . Ravikumar SSK 255; Ibid. , 24.08.2014, S. S . Kambale & K . Ravikumar SSK 293 ( SUK!) .

Conservation status: So far only reported from the type locality where the area of occupancy is less than 10 sq. km. The fragmented populations observed contain a few undivided which are facing severe threat due to habitat destruction. Hence the status is assessed as Critically Endangered [ CR: B2 a, b (iii, iv, v)] .

Notes: Ceropegia ravikumariana resembles both varieties of C. candelabrum . However, it is distinguished from the latter by its elliptic-lanceolate leaves, 2-flowered cymes and gradually dilated corolla tube.

Figures

Fig. 7. Ceropegia ravikumariana Kambale & Gnanasek.: a. Habit; b. Tuber; c. Inflorescence; d. Flower; e. Flower L.S.