Briggsia leiophylla Fang Wen & Y.G.Wei, 2015

Wen, Fang, Maciejewski, Stephen, He, Xiang-Qian, Han, Jing & Wei, Yi-Gang, 2015, Briggsia leiophylla, a new species of Gesneriaceae from southern Guizhou, China, Phytotaxa 202 (1), pp. 51-56 : 51-52

Briggsia leiophylla Fang Wen & Y.G.Wei sp. nov. ( Figs. 1 & 2 A–H )

It differs from Briggsia longipes by only one flower per cyme (rare two), brightly yellow and nearly glabrous corolla, anthers thecae confluent.

Type:–– CHINA. Guizhou Province: Huishui County, growing on damp surface of rock in a limestone cave, 25°49′N, 106°43′E, elevation ca. 1000 m, 10 December 2009 (fl.), Fang Wen 091201 (holotype IBK!, isotype IBK! ANU!).

Description

Perennial herbs. Rhizome subterete, glabrous, with obvious internodes but irregular intervals, 2–8 cm long, 0.3–0.5 cm in diameter. Leaf 5–8 or more, commonly clustered at the top of extended rhizomes, or irregularly alternate on rhizome. Petiole 1–4 cm long, 2–4 mm in diameter, glabrous; The shape of leaf blades changeable, lanceolate, narrow obovate or obovate, oblong, rounded, occasionally spathulate, glabrous, dark green, thin coriaceous, 3.5–15.5 cm × 1.5–10 cm; apex changeable, acute, subacute, obtuse, rounded, mucronate or occasionally retuse, margin entire, lateral nerves 3, rare 4 on each side of the midrib, glabrous, prominent adaxially and abaxially. Cymes 1–2, single flower per cyme, rare double, axillary; peduncle 5–9 cm long or longer, 0.9–1.1 mm in diameter, mint-green, slender, sparsely erect glandulous hairs, hairs 0.3–0.5 mm long; bracts 2, opposite, tiny, green, narrowly triangle, ca. 1.5 × ca. 1 mm, margin entire, apex acute, outside sparsely pubescent, caducous or withered before full-blooming period. Pedicel 9–11 mm long, 0.8–1.0 mm in diameter, hairs and color same as peduncle. Calyx 5-lobed, dissected to the base, segments lanceolate, the top central one ca. 6.0 mm long, base ca. 1.5 mm wide, the others ca. 6 mm long, base ca. 2 mm wide, apex acute, external inconspicuously brownish strumose, but internal glabrous, margin entire; corolla pale yellow to bright yellow, 4–4.5 cm long, orifice 1.4–1.7 cm in diameter, the thickest of corolla ca. 2 cm in diameter, base ca. 3.5 mm in diam., externally glabrous, occasionally very sparsely pubescent, internally glabrous; corolla tube swollen campanulate, externally pale yellow with light brown spot, with dark brown spots inside, gibbous abaxially, 3.8–4.1 cm long; limb distinctly 2-lipped, bright yellow; adaxial lip 2-parted to base, lobes semiorbicular, apex emarginated, ca. 1.1 × 0.5 cm, abaxial lip 3-parted to near middle, the lateral lobes indistinctively obliquely ovate or oval, apex rounded, the central one cordate, apex acute, 0.7–0.9 × ca. 0.6 cm. Stamens 4, the shorter pair of adaxial stamens respectively adnate to ca. 12 mm above corolla tube base, ca. 10 mm long, the longer pair of abaxial stamens respectively adnate to ca. 8 mm above corolla tube base, 14–15 mm long; filaments glabrous; anthers oblong, thecae confluent, glabrous; staminodes 1, adnate to ca. 0.9 cm above corolla tube base, ca. 0.5 mm long. Disc annular, ca. 1.8 mm in height, glabrous, margin subentire. Pistil ca. 2.7 cm long, ovary sparsely glandulosa hairs, narrowly oblong-ovoid, brownish purple, ca. 10 mm long, ca. 1.8 mm in diameter, 1-loculed; placentas 2, parietal, projecting inward, 2-cleft. Style white, ca. 12 mm long, 0.8–1 mm in diameter, glandular-pubescent; stigma 2, equal, undivided, liguliform, 3–4 × 1.5–1.8 mm, apex obtuse, margin irregularly repand. Capsule unseen. Fl. Dec.–Jan.

Distribution:— China (narrow endemic and only known from the type locality, i.e. Duanshan Town, Huishui County (25°49′N, 106°43′E) in south Guizhou Province of SW China.

Habitat & Ecology:— Briggsia leiophylla is known only from the type locality near to Huishui County, Guizhou province. All plants grow on a damp limestone rock in a large cave, at an elevation ca. 1000 m a.s.l. Flowering is in December through January of next year.

Etymology:— This scientific and vernacular name of this new species refers to its glabrous leaf blades.

Vernacular name:— Guāngyè Cūtǒngjǜtái.

Population Status: Initially we only found one population in one locality, in a limestone cave, a narrow area on damp cliff, ca. 20 individuals. Its symbiotic plants mainly are two species of Elatostema J. R. & G. Forst. and one species of Begonia Linn ..

Endangered status: Now only one distributing point survived, and the area is very small. The amount of individuals is seriously smaller than the lowest standard of an endangered status.

Proposed IUCN Category: We carefully investigated the type locality and adjacent regions for many times in past five years. The new species described here appears to be restricted to its type locality, a limestone cave. All individuals are less than 30. Using the IUCN Red List categories and criteria version 3.1 ( IUCN 2001), a provisional conservation status of Critically Endangered ( CR C12 a (i, ii); D; E) is assessed for this species .

Notes:— This species is special at morphology. It can be differentiated from other species in Briggsia because of the extended mode of its rhizomes. Besides this new species, there are two Chinese species in Briggsia are almost glabrous, namely Briggsia mihieri ( Franchet 1885: 450) Craib (1919: 262) and B. longipes (Hemsl. ex Oliv. 1895: 2379) Craib (1919: 262) Burtt. B. leiophylla is similar to B. longipes in several characters, especially in flower ( Figure 3 ). However, it can be easily distinguished by extended rhizomes, commonly one flower on one cyme, corolla yellow, etc ( Table 1).

Additional specimens examined:— Briggsia longipes (Hemsl. Ex Oliv.) Craib : CHINA. Guizhou: Anlong County, Xianheping , 29 October 2012, Fang Wen 121029-3 (IBK); Guangxi: Xing’an County, Baishi village , 13 October 2013, Fang Wen 131013-1 ( IBK). Briggsia leiophylla Fang Wen & Y.G.Wei : CHINA. Guizhou: Huishui County , Duanshan Town , Huishui County, 04 February 2015, Fang Wen & Hua-Fei Cen 150204-1 ( IBK) .

Figures

FIGURE 1. Briggsia leiophylla. A) Habit. B) Different shape of leaf blades. C) Frontal view of corolla. D) Top view of corolla. E) Lateral view of corolla. F) Back view of corolla for showing calyx lobes. G) Opened corolla. H) Stamens and filaments. I) Pistil. J) Stigma.

FIGURE 2. Briggsia leiophylla. A) Habitat. B) Habit. C) Top view of corolla. D) Frontal view of corolla. E) Lateral view of corolla. F) Frontal view of corolla for showing anthers. G) Pedicel and peduncle. H) Calyx lobes. I) Pistil. J) Stigma.

FIGURE 3. Briggsia longipes. A) Habit. B) Cymes and flowers. C) Top view of corolla. D) Frontal view of corolla. E) Lateral view of corolla. F) Pedicel. G) Calyx lobes. H) Pistil. I) Stigma.