Justicia weihongjinii Y. F. Deng, Y. Tong & Y.S. Huang, 2016

Tong, Yi, Huang, Yusong & Deng, Yunfei, 2016, Justicia weihongjinii, a new species of Acanthaceae from Guangxi, China, Phytotaxa 246 (2), pp. 127-136 : 128-130

Justicia weihongjinii Y. F. Deng, Y. Tong & Y.S. Huang , sp. nov. ( Figs. 1–3 )

TYPE:— China. Guangxi: Liujiang Xian, Baipeng Zhen, Fenlong Cun , 260 m, 20 June 2010, Y. F. Deng, Y. Liu, W. B. Xu et Y. S. Huang 21951 (holotype: IBSC! Barcode number 0812474; isotypes: IBK, IBSC) .

Diagnosis:—The new species is similar to J. hainanensis C.Y. Wu & H.S. Lo , J. kwangsiensis (H.S. Lo) H.S. Lo and J. kouytchensis (Lév.) Hossain , but differs by conspicuously undulate leaf-like inflorescence bracts, glabrous calyx with conspicuous wide membranous margin, corolla with pink lower lip and the capsule longer than the calyx.

Description:—Subshrubs, up to 1 m high, with fairly numerous branches. Branchlets stout, quadrangular, sulcate, glabrous or slightly pilose when young, densely punctate with grayish white strip-like cystoliths. Leaves opposite; petioles 3–10 mm long, glabrous; blades thickly papery, obovate-elliptic, 2–4.5 × 1–2.5 cm, base rounded, margin undulate, apex acue, glabrous on both surfaces, adaxially dark green, densely punctate with grayish white stripe-like cystoliths, abaxially pale green, midvein prominent on both surfaces, secondary veins 3–5 on each side of midvein. Spikes borne on the leaf axil, abbreviated, usually 3-flowered, several clustered, sometimes solitary. Inflorescence bracts leaf-like, subrounded, 4–10 mm in diam., shortly petiolate and pinnatinerved, margin undulate, apex obtuse or retuse, densely punctate with grayish white strip-like cystoliths. Bracts and bracteoles subulate or triangular, glabrous. Calyx 6–8 mm long, 5-lobed almost to the base, segments lanceolate, apex acuminate, with conspicuous membranous margins, glabrous, densely punctate with grayish white strip-like cystoliths. Corolla 1.2–1.8 cm long, tube and upper lip white, lower lip pink with white pinnate patches on the throat, throat sparsely pubescent outside, basal tube 0.8–1.2 cm long, limb 2-lipped, upper lip triangular, 1–1.2 × 0.4–0.5 cm, minutely 2-lobed, lower lip suborbicular,1.2–1.5 × 0.5–0.6 cm, 3-lobed, lobes imbricate. Stamens 2, exserted; filaments ca. 2.2 cm long, glabrous; anthers bithecous, thecae superposed, the upper one muticous at base, the lower one with a short white appendage at base. Disc bowlshaped. Ovary glabrous, fusiform; style ca. 2.5 cm long, sparsely pubescent; stigma slightly 2-lobed. Capsule fusiform, glabrous, ca. 1 cm long, apex acute. Seeds 4, compressed, ovate in outline, ca. 1.5–2.5 × 1.4–2 mm, yellowish-brown, testa tuberculate.

Distribution and habitat:— Justicia weihongjinii is only known from the type locality, Liujiang Xian, Guangxi Zhuang Autonomous Region, China ( Fig. 4). It grows in the thickets on the limestone hills ( Fig. 2 : A, B) at elevations of 230– 270 m.

Phenology:—The new species was observed in flowering from June to August and fruiting from July to October.

Etymology:—The species is named after Mr. Wei Hongjin (CSH), who is the first one to discover the new species. He took photographs to upload the website of CFH and the social network QQ and drew our interesting in this new species.

Additional specimens examined (Paratypes):— CHINA. Guangxi: Liujiang Xian, Baipeng Zhen, Fenlong Cun , on limestone hills, in the thicket, 270 m, 22 August 2011, Y. F. Deng & L. Wu 22799 ( IBSC) ; same locality, 250 m, on limestone hills, in the thicket, 28 August 2010, W. B. Xu, Y. Liu & H. J. Wei 10971 ( IBK, IBSC) ; same locality, 250 m, 28 August 2010, W. B. Xu, Y. Liu & H. J. Wei 10973 ( IBK, IBSC) ; same locality, 11 September , 2014, Y. Tong 14091101 ( IBSC) .

Conservation status:—Currently, the new species is known only from the type locality, and the population size of this new species is about 100 mature individuals. It seems that the new species can be accessed to be Endangered (EN) according to the IUCN Red List categories and criteria ( IUCN 2001, 2012). However, the area around the locality where the new species was founded is poor investigation area in Guangxi, the further investigation is necessary since we did not do more field works to seek the new species, therefore we prefer to classified it to be “Data Deficient” (DD) for the present.

Figures

FIGURE 1. Justicia weihongjinii. A. Flowering branch; B. Inflorescence bract; C. Bract; D. Bracteoles; E; Calyx and pistil; F. Opened corolla showing androecium; G. Stamen showing anther; H. Capsule with calyx; I. Capsule; J. Seed. (A–B, E–J drawn by Zhu Yunxi from the holotype Y.F. Deng 21951; C–D drawn by Cui Dinghan from Y. Tong 14091101).

FIGURE 2. Justicia weihongjinii. A. Habitat; B. Habit; C. Flowering branch; D. Inflorescence; E. Pollen grain; F. Exine ornamentation of pollen grain; G. Seed; H. Seed testa.

FIGURE 3. Justicia weihongjinii. A. Adaxial surface of leaf blade; B. Abaxial surface of leaf blade; C. Inflorescence bract; D. Bract; E. Bracteoles; F. Flower; G. Calyxand pistil; H. Opened corolla showing androecium; I. Stamen showing the appendage at the base; J. Pistil and nectariferous disc; K. Stigma; L. Capsule with calyx; M. Lateral view of opened capsule; N. seed.