Bot. Bull. Acad. Sin. (1999) 40: 49_52
Peng and Hu — Lysimachia chingshuiensis, a new species from Taiwan
Lysimachia chingshuiensis (Primulaceae), a new species from eastern Taiwan
Ching-I Peng1,3 and Chi-Ming Hu2
1Institute of Botany, Academia Sinica, Nankang, Taipei 115, Taiwan
2South China Institute of Botany, Academia Sinica, Guangzhou, Guangdong, China
(Received October 14, 1998; Accepted November 9, 1998)
Abstract. A new species of Lysimachia, L. chingshuiensis C.-I Peng & C. M. Hu, from Taiwan is described and illustrated. This species is found on the gravelly summit of Chingshuishan, a metamorphosed limestone mountain in Taroko National Park, ca. 2,200_2,400 m in elevation. It is very rare, presently known only from the type locality. Lysimachia chingshuiensis is a distinct species in sect. Nummularia (Gilib.) Klatt., somewhat similar to L. deltoidea Wight of NE India, Sri Lanka and SW China, but distinct in its subsessile, subcoriaceous leaves with revolute margins, and flowers subsessile, solitary in the axils of the uppermost leaves. A key is provided to aid in the identification of the ten species of Lysimachia indigenous to Taiwan.
Keywords: Chingshuishan; Limestone flora; Lysimachia chingshuiensis; New species; Primulaceae; Rare species; Taiwan; Taxonomy.
The genus Lysimachia consists of about 180 species mainly in temperate and subtropical areas of the northern hemisphere, of which 138 occur in mainland China (Hu and Kelso, 1996) and nine in Taiwan (Kao and DeVol, 1978). Recently, in our botanical inventory of Taiwan we discovered on the summit of Chingshuishan, a metamorphosed limestone mountain in Taroko National Park, an additional species heretofore unknown to science, which is described here.
Lysimachia chingshuiensis C.-I Peng & C. M. Hu,
sp. nov. —TYPE: Taiwan, Hualien Hsien, Hsiulin Hsiang, Taroko National Park,
on exposed rocky slope at peak of Chingshuishan, 121°38'36" E, 24°14'69" N,
ca. 2,200_2,400 m alt., 2_3 Jun 1993, W. P. Leu 1780 (holotype: HAST;
isotypes: A, MO).
Figure 1
Species distinctissima, inter species sectionis Nummulariae L. deltoideae Wight subsimilis, sed foliis sessilibus, subcoriaceis, floribus ad apicem caulium ramorumque in inflorescentias capitulatis congestis valde diversa.
Perennial herbs. Stems herbaceous, covered with articulate, crisp, rusty hairs. Lower stems stoloniferous, slender, elongate prostrate, to 60 cm long, with diminutive leaves ca. 2 mm long, internodes to 2_3.5 cm long, rooting at basal nodes. Upper, flowering stems ascending, internodes 0.3_1 cm long; leaves sessile, lower and middle ones opposite, narrowly elliptic, 4_8 mm long, 1.5_2.75 mm wide,
apex obtuse, base broadly cuneate, often somewhat auriculate and subamplexicaul, margins evidently revolute, subcoriaceous, upper surface glabrous and green, lower surface reddish purple, sparsely hairy as on stem, glabrous; midrib impressed adaxially, manifestly elevated beneath, lateral nerves invisible; uppermost leaves subverticillate, ovate-lanceolate, 7_10(_14) mm long, 3_5(_5.5) mm wide, base attenuate to subrounded, upper surface glabrous and green, lower surface brownish. Flowers subsessile, solitary in the axils of the uppermost leaves. Pedicel less than 1 mm long. Calyx ca. 5 mm long, appressed pubescent mainly along midrib abaxially, divided almost to base, lobes lanceolate, apex acute. Corolla yellow, ca. 10 mm long, widely open; tube 1 mm long; lobes obovate-elliptic, to 5 mm wide, apex rounded, dotted with minute, reddish glands. Filaments connate at base into a ring, ring 0.5 mm long, free part ca. 1 mm long; anthers ca. 1.25 mm long, longitudinally dehiscent. Ovaries globose, glabrous. Styles to 3.5 mm long. Caspules ca. 2.5 mm in diam., brown, dehiscing by 5 valves. Flowering May_Jun; fruiting Jul_Aug.
Additional specimen examined. TAIWAN. HUALIEN HSIEN: Hsiulin Hsiang, Taroko National Park, at summit of Chingshuishan, a limestone mountain, very rare, 121°38'36" E, 24°14'69" N, ca. 2,300 m alt., 23 Jul 1993, Ho 1250 (HAST).
Distribution and notes. Extremely rare, presently known only from the gravelly summit of Chingshuishan, Taroko National Park, Hualien, Taiwan (Figure 2). Lysimachia chingshuiensis occurs in open to semi-shady, mossy or lichened habitat, often with abundant leaf litter, and associated with Juniperus chinensis L. var.
3Corresponding author. Fax: 886-2-2782-7954; E-mail: bopeng@gate.sinica.edu.tw
