Artemisia calcicola X.Q.Guo & L.Wang, 2022

Li, Cheng-Sheng, Chi, Xiao-Rui, Guo, Xin-Qiang & Wang, Long, 2022, Artemisia calcicola (Asteraceae, Anthemideae), a new species from karst region in Guizhou, southwestern China, PhytoKeys 213, pp. 161-167 : 161

Artemisia calcicola X.Q.Guo & L.Wang sp. nov.

Figs 1 , 2

Diagnosis.

Artemisia calcicola is distinguished within the A. subg. Artemisia in having (2- or) 3-pinnatipartite leaves and narrowly ellipsoid involucres 0.9-1.3 mm in diameter. Within this subgenus, it is merely superficially similar to A. annua in having (2- or) 3-pinnatipartite stem leaves, ovate-acuminate or ovate, entire or (1- or) 2-toothed leaf lobules, and a narrow to broad panicle-like synflorescence, but differs by being perennial and by having arachnoid-tomentose stems and leaves and narrowly ellipsoid involucres 0.9-1.3 mm in diameter (a detailed morphological comparison between the two species is given in Table 1 ).

Type.

China. Guizhou: Shibing, Yuntai Shan , 27°06'N, 108°06'E, calcareous cliffs, 873 m a.s.l., 12 October 2021 (fl.), Long Wang & Cheng-Sheng Li 4521 (holotype: IBSC; isotypes: IBSC, PE). Fig. 2 .

Description.

Herbs, perennial, 40-80 (-100) cm tall. Rhizome woody, up to 0.7 cm in diameter at base. Stems arachnoid-tomentose, more or less branched, erect or ascending. Basal stem leaves usually withered at anthesis, petiolate; (2- or) 3-pinnatipartite. Middle stem leaves petiolate; petiole 1-3 cm long; leaf blade ovate or ovate-oblong, 3-7 cm long, 3-5 cm broad, light green adaxially, grayish green abaxially, arachnoid-tomentose on both surfaces, (2- or) 3-pinnatipartite; segments 3-6 pairs, elliptic or ovate-elliptic, 1-2.5 cm long, 0.5-1 cm broad; lobes 3-6 pairs on each segment, elliptic or ovate, 5-8 mm long, 3-5 mm broad, with lobules ovate-acuminate or ovate, entire or (1- or) 2-toothed. Upper stem leaves subsessile or sessile; leaf blade ovate or ovate-elliptic, 3-5 cm long, 3-4 cm broad, (2- or) 3-pinnatipartite, arachnoid-tomentose on both sides; segments 3-7 pairs, elliptic or ovate, 1-2 cm long, 0.5-1.5 cm broad; lobes 3-5 pairs on each segment, elliptic or ovate, 0.5-1 cm long, 3-5 mm broad, with lobules ovate-acuminate or ovate, entire or (1- or) 2-toothed. Uppermost stem leaves subsessile; leaf blade ovate or ovate-elliptic, 1.5-2 cm long, 1.5-2 cm broad, (2- or) 3-pinnatipartite, arachnoid-tomentose on both sides; segments 3-6 pairs, elliptic or ovate, 0.5-1 cm long, 0.5-1 cm broad; lobes 2-4 pairs on each segment, ovate, with lobules ovate-acuminate or ovate, apex mucronate, entire or (1- or) 2-toothed. Synflorescence a narrow or broad panicle. Capitula sessile or subsessile, usually 3-7 clustered together. Involucres narrowly ellipsoid, 1.8-2.2 mm high, 0.9-1.3 mm in diameter. Phyllaries 3-4 rows, abaxially sparsely arachnoid-pubescent (outermost row) to glabrous (inner rows), obovate, ovate-oblong to elliptic, green when fresh, margin membranous. Receptacle glabrous. Marginal female florets 4-6, ca. 2 mm long, fertile; corolla tubular, 0.7-1 mm long, apex 2-toothed; style exserted. Disk florets 7-9, ca. 2 mm long, bisexual, fertile; corolla creamy yellow, 0.8-1 mm long, apex 5-toothed. Achenes cylindrical. Pappus absent.

Distribution and habitat.

Artemisia calcicola is currently known only from the type locality, i.e. Yuntai Shan in Shibing, Guizhou, southwestern China (Fig. 3 ). It grows on calcareous cliffs at an altitude of ca. 900 m above sea level.

Etymology.

Latin calcis, genitive singular of calx, limestone, and cola, dweller, alluding to habitat on calcareous cliffs.

Phenology.

Flowering from October to November; fruiting from November to December.

Vernacular name.

灰岩蒿 (Chinese pinyin: huī yán hāo).

Conservation status.

Artemisia calcicola is currently known only from its type locality, i.e. Yuntai Shan in Shibing, Guizhou, southwestern China. The single population we discovered consists of no more than 20 individuals. Before acquiring adequate information to make a conclusive assessment of its risk of endangerment, the conservation status of A. calcicola is here recommended as "Data Deficient (DD)" (IUCN 2019).

Notes.

In Artemisia subg. Artemisia , A. calcicola is also somewhat similar to A. lancea Vaniot, a species widely distributed in China, India, Japan, Korea, and Russia, particularly in the narrowly ellipsoid involucres. However, A. calcicola differs remarkably from A. lancea by an array of characters, including the arachnoid-tomentose (vs. glabrescent or sparsely arachnoid) stems, (2- or) 3-pinnatipartite (vs. 1-pinnatisect to 3-partite, or undivided), arachnoid-tomentose (vs. adaxially sparsely arachnoid, abaxially densely tomentose) stem leaves, and elliptic or ovate (linear-lanceolate or linear if divided) leaf segments.

Figures

Figure 1. Artemisia calcicola sp. nov. A habitat and habit B leaf rosette of a vegetative branch C portion of stem D leaves E adaxial side of leaf F abaxial side of leaf G portion of synflorescence H capitula I phyllaries (abaxial side) J receptacle K marginal female florets L disk florets. All photographs by Long Wang.

Figure 2. Holotype sheet of Artemisia calcicola sp. nov.

Figure 3. Distribution of Artemisia calcicola sp. nov. (black circle).