Strobilanthes glandulata Nilanthi, 2022

Nilanthi, Rajapakse Mudiyanselage Renuka, Samarakoon, Hiruna, Jayawardana, Nuwan, Hathurusinghe, Bhagya, Wijesundara, Siril & Bandaranayake, Pradeepa Chandani Gunathilake, 2022, Strobilanthes glandulata (Acanthaceae), a new species from Sri Lanka based on the morphological and molecular evidences, Phytotaxa 573 (1), pp. 1-14 : 7-11

Strobilanthes glandulata Nilanthi , sp. nov. (Figures 5 & 7)

Type:— SRI LANKA. Central province: Kandy District, Madugoda , 14 Feb 1928, Alston 1966 (holotype PDA!) .

Diagnosis:— Strobilanthes glandulata is closely related to S. lupulina (Figure 6 & 8).but differs by having slender rounded (not stout quadrangular) stem, ovate (not broadly elliptic) leaves, leaf margin dentate (not serrate), flowers in oval-elongated heads (not in short heads), bracts well-spaced (not compact), margin crenate (not entire), and 3-4 ribs which are completely encircle the poles of pollen (all ribs joined at poles)

Description:— Shrubs, 1–2 m high. Stem slender, rounded, glabrescent below, hispid-pubescent above, muchbranched, young shoots pale green, becoming dark brown when old. Leaves unequal, variable in size; blades ovate, 3–14 × 1.5–8 cm, apex acuminate, base attenuate, margin dentate, hispid on the upper surface, bullate above, cystoliths numerous, decurrent on the petiole; petioles 1.3–7.5 cm long, hispid. Inflorescences terminal and axillary oval-elongated heads; peduncles 3.5–4 cm long, hispid; heads 4.5–6.1 cm long. Bracts distinct, broadly ovate, obtuse, concave, margin crenate with dotted glands, densely covered with glandular-hairs, lower bracts 3–10 × 2–4 mm, smaller than the upper bracts 10–15 × 4–7.5 mm. Calyx 5–6 mm long, oblong, glabrous, lobes equal. Corolla 21–25 mm long, 8–12 mm wide, pale purple, funnel-shaped, glabrous outside, glandular pubescent inside, lobes ovate, obtuse, 3 mm long, 4 mm wide. Stamens 4, included, 2-longer and 2-shorter, longer stamina filament 15–18 mm long, shorter stamina filament 7–9 mm long, stamina filament pubescent. Pollen ellipsoid, tricolporate, P/E = 1.3, ribs 18, ribs have solid aggregates of raised supratectal elements, endoaperture elongate (Figure 2). Ovary ca. 2× 1 mm, apex pubescent, style 18–22 mm long, filiform, pubescent on lower part; stigma linear, ca. 2 mm long, simple, glabrous. Capsule not seen.

Etymology:— The epithet “ glandulata ” refers to the glandular-hairs on the bracts.

Phenology:— Flowering from March to May.

Habitat:— The new species grows in the shady places among rocks in the banks of streams and edges of nature trails (Figure 9).

Distribution:— It is rather restricted in undisturbed habitat in Rambukoluwa, at an elevation of 282 m towards the eastern slope of the Knuckles Mountain and Madugoda in Sri Lanka. Whereas S. lupulina shows quite widespread distributions at low and high altitudes of the wet zone at an elevation of 100–1800m.

Conservation Status:—From 2016 to 2021, we visited Madugoda for several times. However we were unable to rediscover S. glandulata from Madugoda. Destruction of natural habitats due to agriculture and development projects could be the main reason for the disappearance of this species from the type locality. As a result, the study determined that the only remaining population of S. glandulata is in Rambukoluwa. Approximately, 300 individuals have been noted in the Rambukoluwa area, and it seems that the species is well-adapted to the habitat. There is a threat to this population due to road construction for the Kaluganga project. Therefore, S. glandulata could be classified as Critically Endangered (B1ab, ii, iii, v; B2ab, ii, iii, v) following the IUCN Status Categories under Criterion

Additional specimens of Strobilanthes glandulata examined (paratypes):— Matale District , Eastern slope of Knuckles mountain at Rambukoluwa, E 202704 N 258834, 282 m, 24April 2019, RMRN_123 (PDA!) .

S pecimens of Strobilanthes lupulina examined:—Matale District: Lagalla, Sept 1893, Trimen s.n.. (PDA); Kagalle District: Kalugala, 28 Aug 1927, Alston 877 (PDA); Across river from Kitulgala, 6 Nov 1967, Comanor 540 (PDA); Ambarawella, 23 Aug 1968, Amaratunga 1629 (PDA); Kalutara District: Kalugala, 28 Jun 1975, Waas 1290 (PDA); Kalwana-Agalawatta, 27 mile post, 9 Sep 1975, Sumithraarachchi et al. 1010 (PDA); Kalugala Forest, Pahala Hewessa, 6 Nov 1975, Sohmer & Waas 10276 (PDA); half mile north of Pahala Hewessa, 17 Feb 1977. B. & K. Bremer 810 (PDA), RATNAPURA DISTRICT: Kokawatte, Sinharaja Forest, Dec 1893, Trimen S.N. (PDA); Nuwara Eliya District: Gardner in Thwaites C.P. 254 (PDA); Road from Pundaluoya to highway A5 and Nuwara Eliya, 26 Dec 1970, Theobald & Krahulik 2818 (PDA).