Cremanthodium principis ( Franchet 1896: 412 ) Good (1929: 283)

Wang, Long, Ren, Chen & Yang, Qin-Er, 2018, Rediscovery of Cremanthodium principis (Asteraceae, Senecioneae) in northwestern Yunnan, China, Phytotaxa 343 (3), pp. 277-282 : 280-281

Cremanthodium principis ( Franchet 1896: 412) Good (1929: 283) . Figs. 1−3 .

Type:— CHINA. Yunnan: Lushui-Yunlong pass, Lushui City, ca. 3800 m a.s.l., 11 July 1895, Prince Henri d’Orléans s.n. (holotype!).

Perennial herbs. Rhizomes short, with fleshy roots. Stem solitary, erect, to 35 cm tall, 1.5−2 mm in diam. at base, proximally glabrous, distally puberulent and lanuginous. Basal leaves petiolate; petiole to 10 cm; leaf blade square to ovate, 3.3−5.0 cm long, 3.1−5.0 cm wide, adaxially glabrous, abaxially reddish wooly-tomentose, pinnately veined, margin indistinctly sinuate-dentate. Stem leaves 7−16, not sheathed; proximal stem leaves 2−5, petiolate; petiole to 10 cm long; leaf blade square, oblong or ovate-oblong, 4.0−5.0 cm long, 3.0−5.0 cm wide, adaxially glabrous, abaxially densely woolly-tomentose, pinnately veined, base cordate, margin indistinctly sinuate-dentate, apex rounded, obtuse or emarginated; middle to distal stem leaves 5−14, distally smaller, sessile, bracteal, lanceolate to linear. Capitulum solitary. Involucre hemispheric, 4.5−5.0 cm in diam., ca. 3 cm high, dorsally papillose hairy; phyllaries 13−15, in 2 rows, outer ones lanceolate, 1.4−1.5 cm long, ca. 0.4 cm wide, apex acute, inner ones oblong, 1.3−1.4 cm long, ca. 0.6 cm wide, margin brown membranous, apex acute. Ray florets yellow, 13−14; lamina oblanceolate, 2.3−2.6 cm long, 0.6−0.8 cm wide, markedly 3-dentate or 3-lobed, apex truncate, apex of lobes acute. Tubular florets numerous, yellow, ca. 7 mm long; tube ca. 2 mm long; limb ca. 6 mm long; style ca. 1.3 cm long. Pappus white, as long as tubular corolla. Achenes (not perfectly mature) obovoid, ca. 2.5 mm long.

Phenology: —Flowering from July to August, fruiting in September.

Additional specimen examined: — CHINA. Yunnan: Lushui, Daxindi Zhen, Lushui-Yunlong pass, Lamaku Shan, gravelly grassy slope, 3800 m a.s.l., L. Wang & Y.Y. Shao 1609 (IBSC).

Conservation status: — Cremanthodium principis is endemic to northwestern Yunnan, one of the core areas of the Hengduan Mountains region in southwestern China, which is well-known for its very rich flora and high endemism of seed plants ( Wu 1988, Li & Li 1993) and is recognized as a biodiversity ‘hot spot’ ( Boufford & van Dyck 1999, Myers et al. 2000). This species is known only from its type locality, i.e. the Lushui-Yunlong pass, Lushui City, northwestern Yunnan, China. The population we found covers only an area of about 100 m 2, including approximately 250 individuals. According to the IUCN red list categories and criteria, version 3.1 ( IUCN 2001), this species should be categorized as a critically endangered species (CR). Fortunately, the type locality is not easily accessible. It took the first author two days to walk from the nearest village to the type locality. After its first discovery 121 years ago, C. principis still survives in its type locality.

Note s:—According to Liu’s (1982, 1989) infrageneric classification of the genus Cremanthodium Bentham (1873: 38) , C. principis , which has square or oblong, pinnately-veined leaves and oblanceolate ray laminae with a truncate apex, should be placed in C. ser. Cuneata Ling & Liu in Liu (1982: 52) under C. sect. Pinnatinervia Ling & Liu in Liu (1982: 51; “ Pinnatinervus ”). Morphologically this species is most closely similar to C. trilobum Liu (1984: 61) and C. sino-oblongatum Good (1929: 288) in the same series. From the former it can be distinguished by the basal leaves reddish woolly-tomentose (vs. glabrous) abaxially, margin indistinctly sinuate-dentate (vs. crenate-dentate), the stem leaves 7−16 (vs. 3−7), the phyllaries papillose hairy (vs. shortly brown pilose to glabrescent) outside, and the pappus white (vs. pale brown); from the latter it differs by the stem puberulent and lanuginous (vs. brown pilose and white arachnoid) distally, the basal leaves reddish wooly-tomentose (vs. sparsely white pilose) abaxailly, margin indistinctly sinuate-dentate (vs. regularly triangular-dentate or denticulate), and the phyllaries papillose hairy (vs. shortly brown pilose and white arachnoid) outside. Although C. principis and C. gypsophilium were treated as conspecific by Liu (1989), Min (2004), and Liu & Illarionova (2011), these two species might be only distantly related to each other. The latter species has square, pinnately-veined leaves and oblong ray laminae with an acute apex, and thus should belong to C. ser. Oblongata Ling & Liu in Liu (1989: 145) under C. sect. Pinnatinervia.

Figures

FIGURE 1. A newly collected specimen of Cremanthodium principis after 121 years of the first collecting of this species.

FIGURE 2. Cremanthodium principis in the wild (Lushui-Yunlong pass, Lushui, northwestern Yunnan, China).A. Habitat. B, C. Habit.

FIGURE 3. Cremanthodium principis in the wild (Lushui-Yunlong pass, Lushui, northwestern Yunnan, China). A. Basal leaf (adaxial surface). B. Basal leaf (abaxial surface). C. Indumentum on abaxial surface of basal leaf. D. Capitulum (top view). E. Capitulum (bottom view). F. Capitulum (side view). G. Outer phyllaries (abaxial surface). H. Inner phyllaries (abaxial surface). I. Ray florets. J. Tubular florets.