Juncus kuohii, M.J.Jung, 2013

Jung, Ming-Jer, 2013, Juncus kuohii (Juncaceae), a new species from Taiwan, Phytotaxa 81 (2), pp. 49-54 : 49-53

Juncus kuohii M.-J. Jung, sp. nov. ( Figs. 1 A–J & 3 )

TYPE:— TAIWAN. Nantou Hsien: Jen-ai Hsiang, Hohuan Hostel , 121° 17’01” E, 24° 08’33” N, 3210 m, 13 September 2012 , M.- J. Jung 5955 (holotype TAIF!; isotypes HAST!, TNU!).

Juncus kuohii is similar to J. fauriensis in appearance, but can be differentiated by more cataphylls at the base of the plant, the sheath apex with or without inconspicuous auricles, and the dark brownish outer tepals with light or dark central band and castaneous to dark brownish side.

Perennial, 10–40 cm tall, caespitose; rhizome short, horizontal, to 2 cm long; culms terete, rather stout, base bulb-like, nodes 1 or 2; flowering culm 1-noded. Cataphylls 2–5, basal, to 15 cm long, to 2 mm wide, pluritubulose, imperfectly septate, pale greenish to brownish tinged with purplish margin. Cauline leaves 1–2; sheath pale greenish, margin hyaline, membranaceous; auricles inconspicuous or not present, oblong when present, hyaline, membranaceous, to 1 mm long; blade linear, flat, pluritubulose, imperfectly septate, apex obtuse to acute, base narrower than sheath apex, pale greenish to pale brownish, to 6 cm long, to 2 mm wide. Inflorescence terminal, racemose, composed of 3–6 obconical head of 3–6 flowers, on a peduncle 0.5–4 cm long. Lower bract leaf-like, linear, apex acute, to 4 cm long, to 2 mm wide, nearly equal to inflorescence in length. Bract narrowly ovate, 5–5.5 mm long, apex acuminate and mucronate, dark brownish, inconspicuously 3-nerved, margins hyaline, membranaceous; pedicel to 2 mm long, glabrous. Perianth parts 6, equal or nearly equal in length; outer tepals 3, lanceolate to narrowly ovate, apex acute to acuminate, mucronate, 4.5–4.7 mm long, central part pale or dark brownish, sides castaneous to dark brownish, margin membranaceous and hyaline, veinless; inner tepals 3, oblong, apex round, totally dark brownish, veinless, 3.5–3.7 mm long. Stamens 6; filament to 1 mm long, anther ca. 1.1 mm long. Pistil 1, ovary ca. 2.5 mm long, ca. 1.5 mm wide; style to 0.5 mm long, stigma 3-lobed, to 1 mm long. Capsule trigonous, ellipsoid, unilocular, 2.5–3.5 mm long, dark brownish.

Habitat, distribution and IUCN Red List category: — Juncus kuohii M.- J. Jung occurs in grassland in a wetland area, where there is full sun, in a ditch on the ridge at high elevation (about 3210 m) of central Taiwan ( Fig. 2). This species grows into a dense clump. It occurs with Carex nubigena D. Don (1823: 455) and Primula miyabeana Ito & Kawakamii (1911: 1) . Only one population was found, and its distribution is less than 1 km 2. According to the IUCN Red List criteria ( IUCN 2001), J. kuohii should be categorized as Critically Endangered ( CR).

Etymology: —The author dedicates this new Juncus species to Dr. Chang-Sheng Kuoh, the agrostologist and former vice-professor of Department of Life Sciences, National Cheng-Kung University. The specific epithet recognizes his keen interest and substantial contribution to the study of Taiwanese dicotyledonous and monocotyledonous families and his significant role in editing the Flora of Taiwan covering both the native and naturalized flora.

Morphological comparison: — Juncus kuohii is similar in appearance to another Juncus species in section Ozophyllum native to northeastern Asia ( Japan to Kamschatca Peninsula): J. fauriensis , comprising two subspecies. However, several diagnostic characters separating these three taxa ( Table 1) were found after relevant vouchers and literature ( Buchenau 1906, Kudo 1922, Kirschner 2002) were examined. Juncus kuohii is more similar to J. fauriensis subsp. kamschatcensis ( Buchenau 1906: 159) Novikov (1990: 122) than to subsp. fauriensis , especially in floral characters ( Table 1). Following the classification of Kirschner (2002), J. kuohii would be classified under subgenus Juncus section Ozophyllum .

(Buchenau) Novikov, and J. kuohii M.-J. Jung.

Additional specimens of Juncus kuohii examined (paratypes): — TAIWAN. Nantou Hsien: Jen-ai Hsiang, Military Skiing Training Center , 121° 17’01” E, 24° 08’33” N, 3210 m, 13 July 2000, C.- H . Lin 520 ( HAST!), 121° 17’01” E, 24° 08’33” N, 3210 m, 3 September 2004, W.- C . Leong 3823 ( HAST!), Taroko National Park , 121° 17’01” E, 24° 08’33” N, 3210 m, 24 July 2005, W.- C . Leong 3940 ( HAST!) .

Specimens of J. bufonius examined: — PHILIPPINES. Luzon: Benguet, Atok, Paoay , 20 February 2006, R . Rubite 154 ( HAST!) . TAIWAN. Chia-Yi Hsien: Alishan Hsiang, Alishan Activative Center , 28 October 2000, W.- C . Leong 2104 ( HAST!)

Specimens of J. fauriensis subsp. fauriensis examined:— JAPAN. Tidesan , 30 August 1898, U . Faurie 1803 ( E, isotype, photo) . JAPAN. Aomori Pref.: Kamikita-gun, Towadako-machi, S . slope of a col W. of Sarukura-dake Peak , 140° 53’10” E, 40° 36’40” –50” N, 1330–1340 m, 24 August 2000, K . Yonekura 6139 ( HAST!) .

Specimen of J. fauriensis subsp. kamschatcensis examined:— JAPAN. Aomori Pref.: Kamikita-gun, Towadako-machi, Takadayachi Moor , around Iizumi-numa Pond , 140° 53’10” E, 40° 37’40” –50” N, 1030–1040 m, 3 August 1999, K . Yonekura et al. 99898 ( HAST!) .

Figures

FIGURE 1. Juncus kuohii M.-J. Jung (from the holotype). A. Habit. B. Part of leaf sheath and blade base, showing the auricle, lateral view. C. Head. D. Bracteole. E. Flower with pedicel, lateral view. F. Outer tepal. G. Inner tepal. H. Anther. I. Pistil. J. Cross section of ovary. (drawn by M.-J. Jung)

FIGURE 3. Leaf sections of Juncus kuohii M.-J. Jung (from the holotype). A. Cross section. B. Cross section, enlarged for showing the pluritubulose, imperfectly septum. C. Longitudinal section. (Bar = 100 µm; s: septum).