Primula mianyangensis G.Hao & C.M.Hu, 2013

Wu, Xing, Xu, Yuan, Hu, Chi-Ming & Hao, Gang, 2013, Primula mianyangensis (Primulaceae), a new species from Sichuan, China, Phytotaxa 131 (1), pp. 49-52 : 49-51

Primula mianyangensis G.Hao & C.M.Hu , sp. nov. ( Fig. 1 )

Type: ⎯ CHINA. Sichuan: Mianyang City, An Xian , Cha Ping Xiang , summit of Qian Fo Shan , 31° 74' N, 104° 21' E, 2750 m elev., 20 June 2012, Y . Xu 120112 (holotype: IBSC; isotype: IBSC) .

Species affinis P. kialensi Franch. et P. sociali Chen & C. M. Hu sectionis Aleuritiae Duby, a priore imprimis scapo nullo, foliis longe petiolatis differt; ab altera statura majore, pedicellis ad 5 cm longis, floribus multo maioribus valde diversa.

Herbs, perennial, 5 − 8 cm tall, with a short rootstock covered with the remains of old leaves. Leaves variable, inner leaves smaller, leaf blade obovate to oblanceolate, 0.8 − 1.8 cm long, pale yellow farinose on both surfaces, obscurely toothed above the middle, base gradually tapering into a winged petiole usually as long as the blade; outer leaves long petiolate, petioles 3 − 4.5 cm long, ca. 2 times the length of the leaf blade, not winged; leaf blade elliptic, 1.5 − 3 × 0.6 − 13 cm, membranous when dry, apex obtuse to more or less acute, base attenuate, margin dentate-serrate from lower 1/3, abaxially densely pale-yellow farinose, adaxially glabrous; lateral veins 6−7 on each side of the midvein, reticulation of veins obscure on both surfaces. Scape never develops. Flowers distylous, 2 to many arising from leaf rosette. Pedicels 3.5 − 5 cm, glabrous, with a very small scale-like bract near the base. Calyx narrowly campanulate, 8 − 9 mm, sparsely yellow farinose on both surfaces, 5 − veined, split to 2/3 of its length; lobes lanceolate, apex acuminate. Corolla pale rose − purple, with a pale yellow or white eye; limb 1.8 − 2 cm wide; lobes obovate, 6 − 7 × ca. 6 mm, bilobed, lobules entire; thrum flower with corolla tube ca. 10 mm long, stamens inserted towards apex, style ca. 3 mm long, reaching to the lower 1/3 of the tube. Capsule ovoid-ellipsoid, ca. 5 mm long, shorter than the persistent calyx, opening by valves.

Distribution, habitat and conservation status: ⎯ The new species is currently known only from the type locality in Sichuan, Mianyang City, An Xian, Cha Ping Xiang, Qian Fo Shan (ca. 31° 74' N, 104° 21' E). It grows on moist cliffs of the summit at 2750 m elevation, flowering from May to mid-June. To date, only one population with approximately 500 individuals has been found in an area of 5 km 2. According to IUCN red list criteria ( IUCN 2001), this species should be included in the category‘Critically Endangered’ (CR) (B2abiii).

Etymology: ⎯ The epithet of the new species is taken from the Chinese pinyin, “mianyang”, the name of the city in northern Sichuan, China, and the Latin suffix, “ − ensis,” meaning “of origin or place”, referring the type locality and known distribution of the new species.

Additional specimens examined (paratype): ⎯ CHINA. Sichuan: Mianyang city, An Xian, Cha Ping Xiang , summit of Qian Fo Shan , 3000 m elev., 29 April , 2012, Y . Xu & Y . J . Liu 120056 ( IBSC) .

Discussion: ⎯ In the genus Primula , flowers are usually borne on scapes forming umbellate subcapitate, racemose or spicate inflorescences, but in some species of sections Petiolares Pax (1889: 173) and Minutissimae Pax (1889: 202) the scapes initially are not fully developed and hidden in the leaf-rosette, while after anthesis they elongate and become conspicuous. Species with solitary flowers and without a scape, although rather rare, occur in sections Petiolares, Minutissimae and Aleuritia . The new species, being a robust plant with leathery capsule opening by valves, can be easily distinguished from other non-scapose species in sections Minutissimae and Petiolares. In section Aleuritia , P. socialis is similar to P. mianyangensis in having yellow farina and lacking a scape, but the new species is a much robust plant, up to 8 cm tall, with longpetioled leaves and larger flowers. In the general appearance the new species also resembles P. kialensis , but can be easily distinguished by its basal rather than scapose flowers. The main morphological differences between P. mianyangensis , P. socialis and P. kialensis are summarized in Table 1.

Figures

FIGURE 1. Primula mianyangensis. A. the plant; B. calyx (opened); C. corolla dissected to show stamens and pistil (short-styled flower); D. capsule. A−D drawn from Y. Xu 120112. Drawing by Liu Yun-Xiao.