Review Article |
Corresponding author: Xin-Qiang Guo ( xqguo@hznu.edu.cn ) Corresponding author: Long Wang ( lwang@scbg.ac.cn ) Academic editor: Alexander Sennikov
© 2022 Cheng-Sheng Li, Xiao-Rui Chi, Xin-Qiang Guo, Long Wang.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Li C-S, Chi X-R, Guo X-Q, Wang L (2022) Artemisia calcicola (Asteraceae, Anthemideae), a new species from karst region in Guizhou, southwestern China. PhytoKeys 213: 161-167. https://doi.org/10.3897/phytokeys.213.96203
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Artemisia calcicola (Asteraceae, Anthemideae), a new species from karst region in Shibing county, Guizhou province, southwestern China, is described and illustrated. The species can be readily assigned to A. subg. Artemisia in having fertile disk florets and glabrous receptacles. Within this subgenus, A. calcicola is distinguished by having (2- or) 3-pinnatipartite leaves and narrowly ellipsoid involucres 0.9–1.3 mm in diameter. It resembles A. annua to some extent, but differs immediately by the plant duration, stem and leaf indumentum, and involucre shape and size. A detailed description and distribution map of this species are also provided herein.
Compositae, limestone flora, morphology, taxonomy
Artemisia L. (Asteraceae), the largest genus of the tribe Anthemideae, comprises 300–500 species mainly distributed in the northern hemisphere (
During a botanical trip to Guizhou in southwestern China in 2021, we discovered an unusual population of Artemisia in a karst region in Shibing (Fig.
Morphological comparison between Artemisia annua and A. calcicola sp. nov.
A. annua | A. calcicola | |
---|---|---|
Duration | Annual | perennial |
Stem | glabrous, sparsely pubescent | arachnoid-tomentose |
Leaf | glabrous, sparsely pubescent; middle stem leaves 3 (or 4)-pinnatipartite; segments 5–8 (−10) pairs | arachnoid-tomentose; middle stem leaves (2- or) 3-pinnatipartite; segments 3–6 pairs |
Capitulum | shortly pedunculate | sessile or subsessile |
Involucre | globose to hemispheric; 1.5–2.5 mm in diameter | narrowly ellipsoid; 0.9–1.3 mm in diameter |
Marginal female floret | 10–20 | 4–6 |
Disk floret | 10–30; corolla yellow or dark yellow | 7–9; corolla creamy yellow |
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.
For morphological comparison, we critically examined physical or digitalized herbarium specimens of the genus Artemisia deposited at several major herbaria in China including CDBI, HNWP, IBSC, KUN, NAS, PE, SZ, and WUK (acronyms follow
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
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.
Latin calcis, genitive singular of calx, limestone, and cola, dweller, alluding to habitat on calcareous cliffs.
Flowering from October to November; fruiting from November to December.
灰岩蒿 (Chinese pinyin: huī yán hāo).
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).
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.
We thank Dr. Qin-er Yang for his critical comments resulting in substantial improvement of the initial draft of the manuscript. We are grateful to the curators of IBSC, K, KUN, LINN and PE for allowing us to examine their specimens and for research facilities. We would also like to thank Xin-yin Ma for her help during preparation of this manuscript. This work was supported by the National Natural Science Foundation of China (grant no. 31900183) and the Biological Resources Programme, Chinese Academy of Sciences (grant no. KFJ-BRP-017-08).