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Botanical Studies (2011) 52: 359-365.
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Sinosenecio albonervius (Asteraceae), a new species from Hunan and Hubei, China
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Ying LIU1,3, Dai-Gui ZHANG2, and Qin-Er YANG1'*
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1Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road, Tianhe District, Guangzhou 510650, P.R. China
2College of Biology and Environmental Science, Jishou University, Hunan 416000, P.R. China
3State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, P.R. China
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(Received September 8, 2009; Accepted July 2, 2010)
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ABSTRACT. Sinosenecio albonervius Y. Liu & Q. E. Yang, a new species from Hunan and Hubei, China, is described and illustrated. Its chromosome number (2n = 48) is reported here. Its karyotype is formulated as 2n =42m + 2sm + 4st. This new species is similar to S. palmatisectus C. Jeffrey & Y. L. Chen in the posture, the palmately-divided leaves and the epappose achenes, but differs in its leaves shallowly 7-9-palmatilobed to 1/41/3, matte-green adaxial surface, pubescence and white veins, deltoid lobes with remotely denticulate margins; and 9-13 ray florets. Line drawings, distribution map, light microscope (LM) microphotographs of floral characters of S. albonervius, and color photographs of both S. albonervius and S. palmatisectus are provided.
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Keywords: Asteraceae; Chromosome number; Karyotype; Senecioneae; Sinosenecio albomrvius.
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In the course of making a comprehensive survey of Sinosenecio B. Nord. (Senecioneae, Asteraceae) deposited in Chinese herbaria for the first author's Ph.D. project on the systematics and evolution of this genus, one collection kept in the Herbarium of Jishou University (JIU), Huping-shan Expedition 060422008, from the southern slope of the Hupingshan Mountain, Shimen County, Hunan Province, China, caught our attention. At first glance, the plant appeared to be S. palmatisectus C. Jeffrey & Y. L. Chen, a species currently known only from Hefeng County, Hubei Province, due to similarities in their leaf shape, posture, and epappose achenes. A more careful examination however, revealed that the plant in question differed from S. palmatisectus in several characters, such as its upper leaf-lamina pubescence and the remotely denticulate margins of its deltoid lobes. Field studies carried out in Shimen County, Hunan and Hefeng County, Hubei (the type locality of S. palmatisectus) confirmed and increased the list of differences between the population from Shimen and S. palmatisectus, leading us to recognize the population from Shimen as an undescribed species. Further field work resulted in the discovery of another population of this new species from the northern slope of the Hupingshan Mountain in Wufeng County, Hubei Province.
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Sinosenecio albonervius Y. Liu & Q. E. Yang, sp. nov.― TYPE: CHINA. Hunan, Shimen County, southern slope of the Hupingshan Mountain, Hou-shan-ping, alt. ca. 800 m, shady places along margin of mixed evergreen and deciduous broad-leaved forests along streamside in ravine, 12 Apr 2007, Qin-er Yang, Qiong Yuan & Ying Liu 632 (holotype, IBSC; isotypes, HAST, PE).
白脈蒲兒根 Figures 1, 2
Haec species similis Sinosenecioni palmatisecto C. Jeffrey & Y. L. Chen habitu, foliorum laminis palmatim divisis et acheniis laevibus glabris pappo destitutis, sed foliorum laminis supra hebetato-viridibus, pubescentibus, non profunde palmatim 7-9-lobatis, lobis ambitu deltatis margine remote denticulatis, nervis albis, ligulis 9-13 dif-fert.
Description: Rhizomatous herb with leafy stems, stolons absent. Rhizomes ca. 6 mm in diameter. Stems solitary or several, erect, 24-45 cm tall, simple, pubescent or glabrous. Radical leaves long-petiolate; lamina reniform to orbicular-reniform in outline, 3-13x4-13 cm, shallowly palmately 7-9-lobed to 1/4-1/3, palmately white veined, apex acute to obtuse, base shallowly to deeply cordate, submembranous, matte-green above and pale-green beneath, pubescent above, pubescent or sometimes glabres-cent beneath; lobes deltoid, margin remotely denticulate; petioles 8-26 cm long, pubescent or sometimes glabres-cent, base expanded, not auriculate. Upper stem leaves
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*Corresponding author: E-mail: qeyang@scib.ac.cn; Tel: +86-20-37094273; Fax: +86-20-37094273.
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Botanical Studies, Vol. 52, 2011
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smaller, with shorter petioles. Capitula many in apical compound corymbs; peduncles 1-3 cm long, distally expanded, sparsely fulvous-villous. Involucres campanulate, ecalyculate, 7-8 x 8-9 mm. Phyllaries 12-13, uniseriate, oblong-lanceolate, ca. 7x2 mm, apex acuminate or acute,
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sparsely fulvous-villous or sometimes glabrescent, fimbri-ate-ciliate at the apex, herbaceous, green. Ray florets 9-13; corolla tube 2-3 mm long, glabrous; rays yellow, oblong-elliptic, ca. 10 x 3 mm, apically 3-denticulate, 4-veined. Disc florets many; corolla 4 mm long, tube 2 mm long,
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Figure 1. Sinosenecio albonervius Y Liu & Q. E. Yang. A, Habit; B, Phyllary; C, Ray floret; D, Disc floret; E, Stamen; F, Style; G, Style-arms (All from Qin-er Yang, Qiong Yuan & Ying Liu 632, HAST, IBSC, PE).
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LIU et al. ― Sinosenecio albonervius, a new species from China
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limb campanulate; lobes ovate-lanceolate. Anthers ca. 1.7 Additional specimens examined. CHINA. HUNAN:
mm long, base obtuse, appendages ovate-oblong. Style Shimen County, southern slope of the Hupingshan Moun-
arms ca. 0.6 mm long, apex truncate. Achenes cylindrical, tain, Hou-shan-ping, alt. 800 m, along streamside in ra-
ca. 2 mm long, smooth, glabrous. Pappus absent. vine, 22 Apr 2006, Hupingshan Exped. 060422008 (JIU).
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Figure 2. Sinosenecio albonervius Y Liu & Q. E. Yang. A, Habit; B, Inflorescence; C, Capitulum opened, showing florets; D, Leaf; E, Habitat (All from type locality and vouched by Qin-er Yang, Qiong Yuan & Ying Liu 632, HAST, IBSC, PE).
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Botanical Studies, Vol. 52, 2011
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Hubei, Wufeng County, northern slope of the Hupingshan Mountain, Chang-le, Mu-shui-xi, alt. 1,200 m, along
streamside, 28 Apr 2008, Houhe Exped. 080428057 (JIU).
Etymology. The specific epithet 'albonervius' refers to the white nerves of leaves in the new species.
Phenology. Flowering April; fruiting May to June.
Distribution and habitat. Sinosenecio albonervius is currently known from two populations in the Hupingshan Natural Reserve, one on the northern slope within Hubei Province and the other on the southern slope within Hunan Province, China (Figure 3), growing in shady places along streamside at altitudes between 800-1,200 m above the sea level.
Floral micromorphological characters. For observation of the anther endothecial cell wall thickenings and filament collar of Sinosenecio albonervius, heads were boiled in distilled water for 3 min, and then fixed with Carnoy I (glacial acetic acid: absolute ethanol = 1:3). Mature disc florets removed from the fixed heads were dehydrated in 70% ethanol for 30 min and then in 99% ethanol for 1 h before they were treated with 5% NaOH overnight. The anther tissue was isolated from the florets on the slide, flooded with 50% glycerol and a cover slip was applied. Samples were then examined at 200x (filament collar) and 400x (endothecial cell wall thickenings) magnification by light microscopy and photographed.
As shown in Figure 4A, the anther endothecial cell wall thickenings of Sinosenecio albonervius were polarized and radial, with the cells of polarized thickenings being predominant, conforming to the results reported previously for some other species of Sinosenecio, such as S. jishouensis D. G. Zhang, Y. Liu & Q. E. Yang (Zhang et al., 2008), S. baojingensis Y. Liu & Q. E. Yang (Liu et al., 2009) and S. hupingshanensis Y. Liu & Q. E. Yang (Liu et al., 2010). Sinosenecio palmatisectus had also the same pattern of anther endothecial cell wall thickenings (Liu and Yang, 2011b) as S. albonervius. The filament collar of S. albonervius consisted of uniformly sized cells (Figure 4B), which is one of the diagnostic features of the genus
(Nordenstam, 1978; Jeffrey and Chen, 1984).
Chromosome cytology. For chromosome observation, root tips were pretreated with 0.1% colchicine for 2 h before being fixed in Carnoy I (glacial acetic acid: absolute ethanol = 1:3), then macerated in a 1:1 mixture of 45% acetic acid and 1 M HCl at 60°C for 3 min, stained and squashed in Carbol fuchsin.
One population (Houhe Exped. 080428057, JIU) of
Sinosenecio albonervius was cytologically studied. In the interphase nucleus, a few darkly stained condensed bodies were observed, but their boundaries were not clear, because the other part was also stained fairly well but unevenly (Figure 5A). The prophase chromosomes displayed a continuous condensation pattern (Figure 5B). The meta-phase chromosomes were counted as 2n = 48 (Figure 5C). The chromosome number of its putative close relative, S. palmatisectus, is also 2n = 48 (Liu and Yang, 2011a). Ac-
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Figure 3. Distribution of Sinosenecio albonervius (▲).
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Figure 4. Anther endothecial cell wall thickenings (A) and filament collar (B) of Sinosenecio albonervius. A, Polar and radial thickenings, with the polar ones predominant but with few radial ones on the right side; B, Uniformly sized cells (All from Qin-er
Yang, Qiong Yuan & Ying Liu 632, HAST, IBSC, PE).
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Figure 5. Interphase nucleus (A), mitotic prophase (B), meta-phase (C, 2n = 48) chromosomes and karyotype (D) of Sinosenecio albonervius (All from Houhe Exped. 080428057, JIU).
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LIU et al. ― Sinosenecio albonervius, a new species from China
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cording to the nomenclature of chromosomes of Levan et Notes. Although Sinosenecio albonervius may be
al. (1964), S. albonervius had 42 median-centromeric (m), confused with S. palmatisectus (Figure 6) owing to their
2 submedian-centromeric (sm) and 4 subterminal-centro- similarities in posture, palmately-divided leaf-lamina and
meric (st) chromosomes (Figure 5D), i.e. 2n = 48 = 42m + epappose achenes (Table 1), it differs from the latter in
2sm + 4st. that the leaf-lamina is shallowly 7-9-palmatilobed to 1/4-
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Figure 6. Sinosenecio palmatisectus C. Jeffrey & Y L. Chen A, Habit; B, Inflorescence; C, Capitulum opened, showing florets; D, Leaf; E, Habitat (All from type locality and vouched by Ying Liu & Tao Deng 2008006, IBSC, PE).
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Botanical Studies, Vol. 52, 2011
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Table 1. Comparison of Sinosenecio albonervius and S. palmatisectus.
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Lamina reniform to orbicular-reniform
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Lamina reniform in outline, deeply 7-9-
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in outline, shallowly 7-9-palmatilobed
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palmatifid to the middle; lobes oblong-
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to 1/4-1/3; lobes deltoid, remotely
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lanceolate, 2-3-dentate or lobulate
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Matte-green, pubescent, white veined
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Nitid-green, at first sparsely pubes-
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cent later glabrescent, yellowish-green
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Anther endothecial cell wall thickenings
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Ray florets per capitulum
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Shady places along the stream, 800-1,200 m a.s.l
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Moist shady places in forests, 1,400 m a.s.l
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Geographical distribution
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Distributed in Shimen County, NW Hunan and Wufeng County, W Hubei
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Distributed in Badong and Hefeng counties, W Hubei
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1/3 (vs. deeply 7-9-palmatifid to the middle), matte-green above (vs. nitid-green), pubescent (vs. at first sparsely pubescent, later glabrescent), white veined (vs. yellowish-green veined ), the lobes deltoid, margin remotely denticulate (vs. oblong-lanceolate, margin dentate or lobulate) and the ray florets 9-13 (vs. 12-16) (Table 1). Undoubtedly, these two species are closely related as demonstrated by their gross morphology, floral micromorphology as well as chromosome number.
Western Hunan and western Hubei in south-central China are remarkably mountainous and are well known biodiversity hotspots. The recent discovery of four new species of Sinosenecio there (Zhang et al., 2008; Liu et al., 2009; Liu et al., 2010; this paper) indicates that these two regions are far from being well botanized, particularly for a genus like Sinosenecio which is distinguished for the narrow endemism of many of its species (Jeffrey and
Chen, 1984; Liu et al., 2011).
Acknowledgments. We are very grateful to Dr. B. Nor-denstam for his invaluable comments on the manuscript. We thank the Administration Bureau of the Hupingshan Natural Reserve for help in the field and Ms. Liu Yun-xiao for making the drawing. This work was supported by the Knowledge Innovation Project of the Chinese Academy of Sciences (KZCX2-YW-415, KSCX2-YW-Z-0918) and the National Natural Science Foundation of China (Grant no.
30970183).
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Chen, Y. L.1999. Sinosenecio B. Nord. In Anonymous (ed.), Flora Reipublicae Popularis Sinicae 77(1). Science Press, Beijing, pp. 101-141.
Jeffrey, C. and Y.L. Chen. 1984. Taxonomic studies on the tribe Senecioneae (Compositae) of Eastern Asia. Kew Bull. 39: 205-446.
Levan, A., K. Fredga, and A.A. Sandberg. 1964. Nomenclature for centromeric position on chromosomes. Hereditas 52:
201-220.
Liu, Y. and Q.E. Yang. 2011a. Cytology and its systematic implications in Sinosenecio (Senecioneae-Asteraceae) and two closely related genera. Plant Syst. Evol. 291: 7-24.
Liu, Y. and Q.E. Yang. 2011b. Floral micromorphology and its systematic implications in the genus Sinosenecio (Sene-cioneae-Asteraceae). Plant Syst. Evol. 291: 243-256.
Liu, Y, G.X. Chen, and Q.E. Yang. 2009. Sinosenecio baojin-gensis (Asteraceae), a new species from Hunan, China. Bot. Stud. 50: 107-113.
Liu, Y, D.G. Zhang, and Q.E. Yang. 2010. Sinosenecio huping-shanensis (Asteraceae), a new species Hunan and Hubei,
China. Bot. Stud. 51: 387-394.
Liu, Z.Y., Y. Liu, and Q.E. Yang. 2011. Sinosenecio nanchuani-cus (Asteraceae), a new species small in size yet high in chromosome number from Chongqing, China. Bot. Stud.
52: 105-113.
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LIU et al. ― Sinosenecio albonervius, a new species from China
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Nordenstam, B. 1978. Taxonomic studies on the tribe Sene-cioneae (Compositae). Opera Bot. 44: 1-84.
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Zhang, D.G., Y. Liu, and Q.E. Yang. 2008. Sinosenecio jishouen-sis (Compositae), a new species from north-west Hunan, China. Bot. Stud. 49: 287-294.
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1中國科學院植物資源保護與可持續利用重點實驗室（華南植物園）
2吉首大學生物與環境科學學院
3中國科學院植物研究所系統與進化植物學國家重點實驗室
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本文描述了中國湖南、湖北產蒲兒根屬一新種：白脈蒲兒根(Sinosenecio albonervius Y. Liu & Q. E.
Yang)。其體細胞染色體數目為2n = 48 。核型公式為2n = 42m + 2sm + 4st 。本新種在體態、葉7-9裂和
瘦果無冠毛方面與鄂西蒲兒根（S. palmatisectus C. Jeffrey & Y. L. Chen)相似，但以葉片7-9淺裂至1/4
1/3 、裂片三角形、不光亮、具白色葉脈、有柔毛、舌狀花9-13而與後者相區別。本文提供了白脈蒲兒根
的彩色圖版、線繪圖、花部微觀性狀的光鏡照片、地理分佈圖以及鄂西蒲兒根的彩色圖版。
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關鍵詞：菊科；染色體數目；核型；千里光族；白脈蒲兒根。
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