Scleria lithosperma

Scleria lithosperma View in CoL (L.) Sw., Prodr. [O. P. Swartz]: 18. 1788. var. lithosperma . Scirpus lithospermus L., Sp. Pl. 1: 51. 1753. Fig. 2 View Fig

Perennial herbs, rhizomatous. Rhizome creeping, nodulose. Culms erect, unbranched, triquetrous, 30–65 cm tall, glabrous, clothed at base with purplish leaf sheaths. Leaves several; basal leaves sheath-like, bladeless; cauline leaves linear, 6–24 × 0.2–0.4 cm, margin finely toothed, apex acuminate, both surfaces glabrous; leaf sheaths triquetrous, glabrous or pubescent; contraligule triangular, c. 2 mm long, apex ciliate. Involucral bracts leaf-like, up to 12 cm long. Inflorescence poorly paniculate, axillary or terminal; spikelets distant on the panicle, 1–3 in cluster. Nutletbearing spikelets bisexual. Glumes ovate-lanceolate, 2–4 mm long, keeled, apex cuspidate or mucronate,

46 Scleria lithosperma var. lithosperma : an addition to the flora of Nepal

glabrous, brown to rusty brown. Nutlets obtusely trigonous, obovoid-ellipsoid,2.5–3× 1.5–1.8 mm, base cuneate into trigonous structure, apex umbonulate, shiny, smooth, glabrous, white. Hypogynium reduced to a very narrow annular ring, adnate to extreme nut base, brownish.

Flowering and fruiting: Flowering from August to November; fruiting from September to November.

Habitat: This species was found growing in dry soil, in sloping, forested areas in the Chure Hills of Nepal. It was collected from both Shorea robusta C.F.Gaertn. ( Dipterocarpaceae ) mixed forest forest and Terminalia anogeissiana Gere & Boatwr. ( Combretaceae ) dominated forest.

Distribution: It is a very widespread species, native to the tropics and subtropics. In Asia, it is distributed in Bhutan, China, India, Indonesia, Malaysia, Myanmar, Nepal (present record), Philippines, Sri Lanka, Thailand and Vietnam. Further, it is also found on islands in the Pacific and Indian Oceans, as well as in tropical regions of Africa, America, and Australia (Zhang et al., 2010).

Specimens examined: NEPAL, Madhesh province, Dhanusha district , N 26.909°, E 86.199°, 280 m, 07.09.2023 GoogleMaps , K. Joshi, S. G. C., Y. B. Poudel, N. P. Ghimire & Y. Uprety FCM-198 ( KATH, TUCH); Saptari district , N 26.667°, E 86.825°, 178 m, 09.09.2023 GoogleMaps ,

K. Joshi, S. G.C., Y.B. Poudel, N.P. Ghimire, & Y. Uprety FCM-342 (KATH, TUCH).

Notes: The true homology of the hypogynium in Scleria is still not resolved, and the presence or absence of this structure in S. subgen. Hypoporum is still rather unclear (Bauters, 2018).

The description of Scleria lithosperma var. lithosperma presented in this paper is based on only two specimens collected from the Chure region of Madhesh province, Nepal. Further investigation of the species in similar habitats in the Chure region, including the lowlands of Nepal, is necessary to document its detailed morphology and distribution in Nepal. Given that the Cyperaceae are undercollected in Nepal ( Bhandari et al., 2021), more botanical exploration in Nepal could widen the distribution of S. lithosperma var. lithosperma .

The typical variety of Scleria lithosperma differs from the heterotypic variety, Scleria lithosperma var. linearis , by its smooth nutlets. Nutlets in S. lithosperma var. linearis are transversely rugose or irregularly somewhat reticulate with wavy ridges (Zhang et al., 2010). A morphological comparison of S. lithosperma var. lithosperma and another Nepalese species of S. subgen. Hypoporum , i.e., S. pergracilis , is provided in Table 1. In addition to the morphological differences, these two taxa also have differences in their known distribution range in Nepal. S. pergracilis has been collected from the Mid Hills, between the elevation range of 1200–1800 m (Shrestha et al., 2022), and S. lithosperma var. lithosperma from the Chure Hills, between the elevation range of 178–280 m (present record).

Key tO the SpeCieS OF SCleria View in CoL iN Nepal

1. Hypogynium reduced or absent ......................... 2

1. Hypogynium well developed ..............................3

2. Inflorescence paniculate; involucral bracts leaf-like .......................... S. lithosperma var. lithosperma View in CoL

2. Inflorescence spicate; involucral bracts bristlelike ....................................................... S. pergracilis View in CoL

3. Plants perennial, rhizome present ...................... 4

3. Plants annual, rhizome absent ............................ 5

4. Plant much robust; nutlets cancellate; hypogynium lobes obtuse or rounded at apex ................................................................ S. terrestris View in CoL

4. Plant smaller; nutlets smooth or slightly rugulose; hypogynium lobes acute at apex, often bidentate ...................................................................... S. levis View in CoL

5. Glumes beset with long, patent hairs ...... S. rugosa View in CoL

5. Glumes glabrous .................................................. 6

6. Nutlets spherical with dark purplish beak, deeply pitted; hypogynium lobes acuminate at apex .................................................................... S. biflora

6. Nutlets ellipsoid or sub-globose with white beak, not deeply pitted; hypogynium lobes acute at apex ......................................................... S. parvula View in CoL