Scleria parvula subsp. tumanganica Czubarj, 2020

Chubar, Elena A., 2020, Scleria parvula subsp. tumanganica (Cyperaceae), a new taxon from the Russian Far East, Phytotaxa 441 (1), pp. 78-86 : 79-81

Scleria parvula subsp. tumanganica Czubarj , subsp. nov. ( Figs. 1 , 2 )

The new subspecies differs from type subspecies based on features of the disc-lobes: rounded, distinctly not separated, margin entire, not reflexed, and rounded shallow sinuses.

Type:― RUSSIAN FEDERATION. Primorsky Krai, Khasansky District, mount Golubiny Utes, 42°24’43’’N, 130°45’20’’E, wet grassy places, near sea level, [fr.], 13 August 2017, E. A. Chubar s.n. (holotype MIMB No. 35979 [digital image available at https://marbank. dvo.ru/index.php/ru/], isotype VLA!).

Description of the new subspecies:―Plants annual, rigid. Roots fibrous, reddish, rhizome absent. Culms solitary or loosely coupled by roots, 20–45 cm tall, slender, glabrous, trigonous, narrow-winged, apically often spreading. Leaves cauline, 4–6; basal leaves (1–2) reduced to bladeless reddish–brown sheaths, glabrous; lower and middle leaves to 16 cm length, sheathing, with leaf blade linear, 1.5–2 mm wide but apically slightly attenuate, papery, with both surfaces nearly glabrous, margins and central vein scabrous, apex obtuse to acute, scabrous. Sheaths of middle and upper leaves slightly winged, with brownish pubescence or glabrous; contra-ligules semicircular, membranous, obtuse or barely marked, with brownish pubescence. Inflorescences paniculate, with 4(–6) terminally and axillary branches; branches 1.2–4 cm long, distant, erect or the lover ones often pendulous, with few (2–4) unisexual spikelets. Bract narrowly linear, nearly setaceous, keel green, sheathless, as long as or longer than spikelet. Spikelets narrowly ovoid, 3–5 mm length; subandrogynous; female spikelets with (2) 4(–5) glumes and 1 female flower; male spikelets with 4–7 or more glumes and 1 male flower. Glumes ovate-lanceolate, or lanceolate, apically attenuate, membranous, straw-colored to reddish brown and (or) greenish, keel green or not. Achenes subspherical, in upper projection slightly 3-sided, in lateral depressed, 1.2–2 mm in diameter, whitish, pubescent, slender, pitted with regular longitudinally elongates lacunae, sometimes rugolose on the upper part; disc 3-lobed, thick, white, greenish or pale yellowish, ca. 1/3–1/5 of the nutlet height, appressed to nutlet; lobes semi-oval, abruptly contracted and subrounded at apex, distinctly not separated, with rounded shallow sinuses, margin entire and thin, pale, not reflexed; cupula oval, with nearly entire margin. Nutlet apex with short yellowish tip. Stigmas 3.

Etymology:―The new subspecies is named after Korean name “Tumangan”of the Tumen River.

Phenology:―Flowering and fruiting from late July to September.

Habitat and conservation status:―Sedge meadows and swamps, near sea level in the estuarine zone of the Tumen River. Locally common. The Golubiny Utes mount (area 150 ha, around with a 200 m wide buffer zone) is the regional complex Natural Monument.

Discussion:―The specimens of Scleria population from the Tumen River region show overlapping characters of different species in the S. sect. Tessellatae Clarke (1894: 686). According to description above, S. parvula subsp. tumanganica is very closely allied to type subspecies (see Figs. 1 , 2 ), S. tessellata Willdenow (1805: 315) , and S. mikawana Makino (1913: 57) in structure of the nutlet surface. It resembles also to S. novae-hollandiae Böckeler (1875: 120) and S. thwaitesiana Böckeler (1874: 454) in disc shape and disc-lobes form but markedly different from S. mikawana on the same basis ( Table 1). Its smallest nutlets (1.2–1.4 mm in diameter) are sometimes tuberculate in their upper half, in the same way as the S. rugosa Brown (1810: 240) . Externally, all listed species of Scleria are similar in habit, structure of inflorescence, nutlet size, shape, and disc form and were previously included in S. sect. Tessellatae. In the recent classification of Scleria (Camelbecke et al. 2001, Bauters et al. 2016), S. parvula , S. tessellata , S. mikawana , and S. novae-hollandiae are included in S. sect. Foveolidia Rafinesque (1830: 219), but S. rugosa and S. thwaitesiana moved to S. sect. Acriulus ( Ridley 1883: 336) Haines & Lye (1983: 357) . These latter two species are also genetically separated from the S. sect. Foveolidia (see Bauters et al. 2016, 2018). The subspecies described shows significantly less similarity with the other known species of S. sect. Foveolidia. According to Hooker (1900), S. tessellata is very closely allied to S. biflora Roxburgh in Roxburgh & Carey (1832: 573). Clarke (1894) considered S. biflora as a variety of S. tessellata but Kern (1961), however, believed that S. biflora is a well-marked species, readily recognizable by the globose, deeply cancellate, black-tipped nutlet deeply pitted between the long disc-lobes. Clarke (1894) and Blake (1954) considered S. parvula (= S. uliginosa Hochst. ex Böckeler (1874: 471)) as a synonym of S. tessellata . Shuren et al. (2010) recognize the same species also as a synonym of S. tessellata Clarke (1903: 267) , not Willdenow (1805). Based on our study, we agree with Steudel’s (1855), Böckeler’s (1874), and Kern’s (1961, 1974) opinions, and consider S. tessellata and S. parvula as closely related but well distinct species. These two species are deficiently studied on the infraspecific relationships. Perhaps S. parvula subsp. tumanganica is a separate species, but additional studies are needed in its distribution and molecular biology. At this stage of study we follow Brummitt (1990) and Wood et al. (2015) regarding of the status of infraspecific taxa.

According to specimens (PE01200099, PE01200103, and PE01200111 [digital images!]) the northern-most in North East Asia S. parvula populations reach the Tochigi and Nagano prefectures in Honshu Island, Japan. On the Korean Peninsula, this species is widespread in Jeollabuk-do, Jeollanam-do and Gyeongsangnam provinces, and also in Shandong Province, China ( Oh 2007, Shuren et al. 2010). The disjunctions in the Scleria geographical range in the Primorsky Krai and in the central parts of Honshu Island and Korean Peninsula constitutes of 700–900 km.

Figures

FIGURE 1. Holotype of Scleria parvula subsp. tumanganica Czubarj.

FIGURE 2. Scleria parvula subsp. tumanganica. A–C. Lateral and basal view of nutlets. D–E. Terminal and lateral spikelets of inflorescence.