Eriocaulon pandeyana Nampy, Harishma & Vishnu, 2022

Harishma, Kuttukaran Haridasan, Mohan, Vishnu & Nampy, Santhosh, 2022, Eriocaulon pandeyana (Eriocaulaceae), a new species from southern Western Ghats, India, Phytotaxa 539 (3), pp. 273-279 : 274-276

Eriocaulon pandeyana Nampy, Harishma & Vishnu sp. nov. ( Figs. 1 & 2 )

Closely resembles E. ramnadense but differs by having oblong-lanceolate, lobed, acute, hyaline involucral bracts (vs. oblong-obovate, entire, obtuse, black), oblanceolate, acuminate floral bracts (vs. cuneate, obtuse), 3 sub-equal male petals (vs. 3 equal), 3 unequal, slightly hoary female sepals (vs. 2 equal, glabrous) and yellow, elliptic seeds with transversely elongated or isodiametric seed coat cells (vs. pale purple, ovoid seeds with almost transversely elongated).

Type: — INDIA. Kerala, Idukki district, Koymanchola , 10°16’52’’N, 77°08’49’’E, 1457 m, 10 February 2021, Santhosh Nampy & Vishnu Mohan 188713 (holotype: CALI, isotype: CAL) .

Erect, acaulescent herbs. Root stock absent. Leaves rosulate, linear-lanceolate, 3–6 cm long, glabrous, acuminate at apex, margin entire, greenish, straw coloured when dry. Sheath 3.5–4.0 cm long, terete, glabrous; limb lanceolate, c. 0.2 mm long, acute. Head spherical, 0.4–0.7 cm across, off white or cream coloured. Peduncles many, 5–22 cm long, glabrous. Receptacle globose, pilose. Involucral bracts oblong-lanceolate, smaller than floral bracts, 1.2–2.0 × 0.8–1.0 mm, reflexed, margin entire or lobed, acute at apex, truncate at base, chartaceous, glabrous, hyaline, but straw coloured when dry. Floral bracts oblanceolate, 1.7–1.9 × 0.5–1 mm, acuminate at apex, truncate at base, hoary towards apex, chartaceous, hyaline. Male flowers: Pedicel c. 0.5 mm long. Sepals 2 or 3, free, oblanceolate, falcate, 1.0– 1.2 mm long, glabrous, sparsely hairy towards apex; stipe 0.7–1.3 mm long. Petals 3, free, oblong, sub-equal, hyaline, one petal slightly longer than other two, 0.35–1.0 mm long, hoary towards apex, with a black gland. Stamens 6; anthers black, 0.27–0.29 mm long, filament c. 0.5 mm long, white. Female flowers: Pedicels 0.07–0.08 mm long. Sepals 3, free, unequal, 1.5–1.9 mm long, one smaller and narrower than other 2, slightly hoary, blackish at apex; hair 0.4 mm long, oblong; stipe 0.23–0.25 mm long. Petals 3, free, with a black gland at apex, oblanceolate, subequal, hyaline, 1.5–1.7 mm long, hoary at apex, not clawed, stipitate between sepals and petals. Ovary sessile, ovoid, c. 0.5 mm long, style 1.0– 1.2 mm long, stigma 3-fid. Seeds elliptic, c. 0.47 × 0.27 mm, apiculate or acute, yellow, brownish at both ends, cells of seed coat transversely elongated or isodiametric, appendaged, appendages in the form of continuous ribbon like bands from transverse and vertical walls conforming its length; testa granular.

Distribution and ecology:— The new species is hitherto known only from a small area near a stream in Koymanchola in Idukki district in Kerala ( Fig. 3 ). It grows along with E. quinquangulare Linnaeus (1753: 87) , E. truncatum Buchanan-Hamilton ex Martius (1832: 29) , etc. at an elevation of 1457m.

Flowering & fruiting:— January to February.

Etymology:— The specific epithet pandeyana is given in honour of Prof. A.K. Pandey (Vice Chancellor, Mansarovar Global University, Bhopal) for his valuable contribution to Indian Taxonomy.

Provisional conservation status:— The species is known only from a single locality with less than 250 mature individuals. Even though the location comes under a protected area, being a streamside, there is risk of human interference and natural adversities such as flooding. Since adequate data on abundance and distribution are lacking, the species is provisionally assessed as Data Deficient (DD) as per IUCN Red List Categories and Criteria (2012, 2019).

Notes:— The new species belongs to the section VII of Ansari and Balakrishnan (1994, 2009) in having free female sepals, black or dark brown anthers, and transversely elongated seed coat cells with ribbon like appendages on the surface of seeds. There are 13 species in this section from India including the one described here. The differences between the morphologically most similar E. ramnadense are given in diagnosis.

It also differs from E. longicuspis Hooker (1893: 573) by its elongated ribbon-like seed coat appendages and 3 subequal male petals, from E. quinquangulare , E. conicum ( Fyson 1921: 260) C.E.C. Fischer (1931: 1620) , E. martianum Wallich (1832: n.7279), E. palghatense R.Ansari & N.P.Balakrishnan (1994: 111) , E. cherrapunjianum R.Ansari & N.P.Balakrishnan (1994: 113) , E. truncatum , E. edwardii Fyson (1921: 313) and E. cristatum Martius (1832: 28) by having male flowers with 2 or 3 free sepals, from E. raipurense K.K.Khanna, Mudgal & An. Kumar (2001: 413) and E. hamiltonianum Martius (1832: 29) by one narrow, smaller female sepal and hairiness of floral bracts.

Figures

FIGURE 1. Eriocaulon pandeyana: A. Habit; B. Head; C. Involucral bracts; D. Floral bracts; E. Male flowers; F. Male sepals; G. Male petals; H. Stamens; I. Female flower; J. Female sepals; K. Female petals; L. Pistil; M. Seeds (from Santhosh Nampy & Vishnu Mohan 188713) Photos by Harishma K.H.

FIGURE 2. Scanning electron micrograph showing seeds of Eriocaulon pandeyana.

FIGURE 3. Distribution map of Eriocaulon pandeyana (created using QGIS ver. 3.16.3).