蘋果薊屬，東南亞大陸菊科一新歸化屬

沈佳豪 牛幗豪 張國進 付志璽 INTA Angkhana 高天剛

摘?要：該文報道了在泰國北部和中國西南部的菊科一個新歸化屬——蘋果薊屬（Centratherum Cass.）。依據(jù)所采集的標本，詳細描述了該屬在東南亞大陸的唯一代表亞種蘋果薊 ［Centratherum punctatum Cass. subsp. fruticosum (S. Vidal) K. Kirkman ex Shih H. Chen, M. J. Wu & S. M. Li］，并配以插圖。蘋果薊與其所在屬的其他種的區(qū)別在于該亞種葉片菱形至橢圓形，葉緣具不規(guī)則鋸齒，先端微尖，總苞片基部硬化，先端無芒。文中還提供了蘋果薊的分布圖，并討論了其可能的傳播途徑。

關鍵詞： 蘋果薊屬， 菊科， 斑鳩菊族， 歸化屬， 東南亞大陸， 命名法

In a field trip to Thailand in May 2014, we collected an unknown taxon of the tribe Vernonieae of Aste-raceae. Similar specimens were also collected in an expedition to Yunnan, China in April 2017. We identified these specimens as Centratherum punctatum Cass. subsp. fruticosum (S. Vidal) K. Kirkman ex Shih H. Chen, M. J. Wu & S. M. Li, a genus and a subspecies not previously recorded in the mainland of Southeast Asia. Centratherum Cass. but a tropical genus distributed in tropical America, Australia and Philippines (Kirkman, 1981). C. punctatum subsp. fruticosum is native to Philippines and can be distinguished from the other taxa of this genus by its leaf blade rhombic to elliptic, leaf margins irregularly serrate, leaf apex broadly acute, and phyllaries indurate at base and not awned (Kirkman, 1981; Chen et al., 1999).

Based on the specimens collected during the flo-wering phase, we provided the description as below.

Centratherum punctatum Cass. subsp. fruticosum (S. Vidal) K. Kirkman ex Shih H. Chen, M. J. Wu & S. M. Li in Taiwania 44(2): 300. 1999 (Figs. 2-4).

≡Centratherum fruticosum S. Vidal, Rev. Pl. Vasc. Filip. 159. 1886; Elmer in Leafl. Philip. Bot. 1: 88. 1906.

Type: —PHILIPPINES. Distr. Lepanto (Mt. Province), 1876, S. Vidal 1502 (syntypes: A photo!［No. A00004641］, L photo!［No. L.3034111］, MA photo!［No. MA728008］).

=Centratherum punctatum Cass. subsp. fruticosum (Elmer) K. Kirkman in Rhodora 83: 20. 1981, nom. inval.

Type: —PHILIPPINES. Prov. Batangas, Luzon, 1841, H. Cuming 1556 (lectotype (designated by Kirkman, 1981): G photo!［No. G00223244］; isolectotypes: E photo!［No. E00417342］, K photo!［No. K000796695］, LE photo!［No. LE00017869, LE00017870］).

Perennial herbs or subshrubs, up to 1-1.4 m tall, branched (Fig.1: A). Stem woody glabrous at base, young shoot hirsute, ridged. Leaves crowded, short internodes often appear fascicled, leaf blade elliptic-obovate to rhombic, 1-8.3 × 0.5-3.9 cm, broadly acute at apex, attenuate to truncate at base, margin irregularly crenate-serrate, uniseriate and T-shaped trichomes on both surfaces; petiole up to 2 cm, winged, indistinct in small blades. Capitula terminal or terminal on axillary branches, 2-2.8 cm in diam., 1.8-2 cm tall; peduncle 3-11 cm long, pubescent, receptacle naked; involucre campanulate to sub-globose, ca. 1 cm tall, base with leafy whorled bracts; phyllaries imbricate in 5-7 series, minutely pubescent, 3-veined, inner phyllaries linear-oblanceolate to fiddle-shaped, 8 × 2.5-2.7 mm, apex mucronate to cuspidate, margin scarious, outer phyllaries triangular, 5-7 × 1-1.2 mm, apex spine or acuminate, base indurate (Fig.1: B). Capitulum with many florets, hermaphrodite, regular. Corolla tubular, reddish-purple, 8-16 mm long, outer part with glandular hairs, lobes 5, linear-lanceolate (Fig.1: C). Style white, style-branches filiform, flushed with purple and hispidulous (Fig.1: D). Stamens 5, white; anthers linear, 3 × 0.5 mm, appendant lanceolate, base calcarate (Fig.1: E). Achene obconic-cyclindrical, ca. 2.5 × 1.5 mm, black, glabrous, with 10 ribs. Pappus of 6-10 bristles, deciduous, straw-colored, 2-3 × 0.2 mm.

Phenology: Flowering and fruiting throughout the years.

Specimens examined: THAILAND. Chiang Mai: Maesai to Nan, alt. 364 m, 99°51′32″ E, 20°12′17″ N, 14 May 2014, Tiangang GAO & Guojin ZHANG 5807 (PE). CHINA. Yunnan: Dehong Autonomous Prefecture, Ruili City, Wanding Town, Huihuan Village, alt. 935 m, 98°2′40″ E, 24°7′4″ N, 1 April 2017, Jinpu WEI et al. RL0832 (HCNGB). (Fig. 2)

In Asia, Centratherum punctatum Cass. subsp. fruticosum (S. Vidal) K. Kirkman ex Shih H. Chen, M. J. Wu & S. M. Li was recorded in Taiwan (Chen et al., 1999) and West Bengal (Chowdhury & Das, 2012). But it has never been recorded in the mainland of Southeast Asia. Besides the present distribution sites (Southwest China and North Thailand), it could also possibly be discovered in the nearby places (like Myanmar) in the future. It may be dispersed to the continent of Southeast Asia by flower trade, as marketing information about it can be obtained in two big business websites of China (Jingdong, 2018; Taobao, 2018). Hitherto, C. punctatum subsp. fruticosum has not been reported as an invasive species. However, based on our field observations, it could produce an immense number of mature achenes (ca. 150) in one capitulum. In addition, because of the vegetational and climatic similarities between mainland of Southeast Asia and origin distribution (Zhang et al., 2017), close attention should be paid to its potential dispersal.

Note:Centratherum fruticosum was validly published by Vidal (1886) with indicating a single gathering (Vidal 1502). Quisumbing (1958, in sched.) labeled one specimen of this gathering (MA［No. MA728008］) as “type”, the other (A［No. A00004641］ as “isotype”, but no effective publication was found. According to Art 7.9 and 9.5 of ICN (McNeill et al., 2012), these three specimens from a single gathering should be treated as syntypes. In 1906, Elmer used the name C. fruticosum S. Vidal by giving a full and direct refe-rence, and cited the specimens Cuming 1556 and Elmer 5956. In 1981 Kirkman established the new combination C. punctatum Cass. subsp. fruticosum (Elmer) K. Kirkman based on the incorrect author and reference citation. In addition, Kirkman designated Cuming 1556 (G［No. G00223244］) as lectotype of C. punctatum Cass. subsp. fruticosum (Elmer) K. Kirkman and described it only in English. According to the Art 39.1, 41.5 and 41.8(d) of ICN (McNeill et al., 2012), as a new taxon name, C. punctatum subsp. fruticosum K. Kirkman was invalidly published because of no Latin description or diagnosis. Hence, the new combination C. punctatum subsp. fruticosum (Elmer) K. Kirkman was invalidly published because of the indirect reference. In 1999, Chen et al. cited Kirkman’s publication but clearly indicated the correct basionym C. fruticosum S. Vidal with a full and direct reference. Hence, C. punctatum Cass. subsp. fruticosum (S. Vidal) K. Kirkman ex Shih H. Chen, M. J. Wu & S. M. Li was the valid name. The result is coincident with that of Chowdhury & Das (2012).

Acknowledgements?We are indebted to the curators of the herbarium PE and HCNGB for access to specimens.

References:

CHEN SH, WU MJ, LI SM, 1999. Centratherum punctatum Cass. ssp. fruticosum, a newly naturalized sunflower species in Taiwan ［J］. Taiwania, 44: 299-305.

CHOWDHURY M, DAS AP, 2012. Record of naturalization of Centratherum punctatum Cassini ssp. fruticosum (S. Vidal) K. Kirkman (Asteraceae) in India with a note on its nomenclature ［J］. J Bot Soc Bengal, 66: 69-71.

ELMER ADE,1906. Manual of the Philippine Compositae ［J］. Leafl Philip Bot, 1: 83-186.

JINGDONG, 2018［2018-07-01］.［EB/OL］. https://item.jd.com/24598283886.html.

KIRKMAN LK,1981. Taxonomic revision of Centratherum and Phyllocephalum (Compositae: Vernonieae) ［J］. Rhodora, 83: 1-24.

MCNEILL J, BARRIE FR, BUCK WR, et al., 2012. International Code of Nomenclature for algae, fungi, and plants (Melbourne Code) adopted by the Eighteenth International Botanical Congress Melbourne, Australia, July 2011 (Regnum Vegetabile 154) ［M］. Knigstein: Koeltz Scientific Books.

TAOBAO, 2018［2018-07-01］.［EB/OL］. http://m.tb.cn/h.WuTJpcx.

VIDAL S, 1886. Revision de plantas vasculares Filipinas ［M］. Manila: Establecimiento Tipo-Litográfico de M. Perze: 159.

ZHANG X, WU S, YAN X, et al., 2017. A global classification of vegetation based on NDVI, rainfall and temperature ［J］. Int J Climatol, 37: 2318-2324.