A new record of Galium bungei var. miltorrhizum (Hance) Jeong & Pak (Rubiaceae) in Korea

Article information

Korean J. Pl. Taxon. 2017;47(1):23-26
Publication date (electronic) : 2017 March 31
doi : https://doi.org/10.11110/kjpt.2017.47.1.23
Division of Forest Biodiversity, Korea National Arboretum, Pocheon 11186, Korea
1Department of Forest Conservation, Korea National Arboretum, Pocheon 11186, Korea
2Research Institute for Dok-do and Ulleung-do Island, Kyungpook National University, Daegu 41566, Korea
*Author for correspondence: kchoi69@korea.kr
Received 2017 January 31; Revised 2017 February 21; Accepted 2017 March 17.

Abstract

We reported an unrecorded plant species, Galium bungei var. miltorrhizum (Hance) Jeong & Pak in Korea. This species is found in Gyeonggi-do, Chungcheongbuk-do, Jeollabuk-do, Gyeongsangbuk-do, and Gyeongsangnam-do. G. bungei var. miltorrhizum is distinguished from related taxa by glabrous stem and glabrous or rarely short papillate mericarps. This taxon was named ‘Dung-geun-ne-ip-gal-kwi’ in Korean based on shapes of leaves. We provided a description, illustrations, photographs, and a key of related taxa in Korea. And we propose a new combination (Galium bungei var. miltorrhizum).

Genus Galium L., the largest genera in the tribe Rubieae of the Rubiaceae, is comprises about 650 species distributed predominantly in temperate regions of the world (Ehrendorfer et al., 2005).

The genus Galium includes annual and perennial herbs characterized by leaves in whorls of 2-4, 3 or 4-lobed corollas, rudimentary corolla tubes, and dry mericarps (Elkordy and Schanzer, 2015). Identification of the taxa in this genus is difficult because of the considerable morphological variations (Pobedimova, 1958). Based on morphological characters, including ovary and fruit indumentum, leaf shape, and inflorescence, 16 sections are recognized within the genus (Ehrendorfer et al., 2005). The section Platygalium W. Koch consists of about 70 taxa distributed in Asia and America (Chen and Ehrendorfer, 2011). This section is characterized by leaves in whorls of 4 and terminal and axillary cymes and/or panicles 3–20 flowers (Dempster and Stebbins, 1968; Ehrendorfer et al., 1976, 2005; Dempster, 1981; Ehrendorfer and Schönbeck-Temesy, 1982; Yamazaki, 1993). The type of indumentum of the ovary and fruit is important taxonomic character for identification of species in the sect. Platygalium (Elkordy and Schanzer, 2015).

Galium bungei Steudel (sect. Platygalium) is an annual herb with leaves in whorls of 4 and rotate corollas. The species is widely distributed in eastern Asia (Yamazaki, 1991; Chen and Ehrendorfer, 2011). Chen and Ehrendorfer (2011) recognized 6 varieties within G. bungei based on the shape of leaves and the morphology of hairs on the stem, node, and leaves based on classification of Cufodontis (1940).

While conducting the revision of the genus Galium, we discovered an unrecorded plant in Korea; however, researches on these species in China and Japan been already been published several times elsewhere (Yamazaki, 1991; Chen and Ehrendorfer, 2011). The unrecorded variey of genus Galium, Galium bungei var. miltorrhizum (Hance) Jeong & Pak, are reported to exist in Korea for the first time and are described and illustrated in detail. In addition, we provide an identification key for the sect. Platygalium.

Taxonomic Treatment

Galium bungei var. miltorrhizum (Hance) Jeong & Pak, comb. nov. (Fig. 1)

Fig. 1.

Galium bungei var. miltorrhizum habit with a inflorescence and leaves on stem. A. Flower. B. Fruit. C. Seed. D. Leaf. E. Leaves at node. F. Stem. WP - Whole plant.

Galium miltorrhizum Hance, J. Bot. 6: 114, 1868; Galium gracile var. miltorrhizum (Hance) Loes., B.B.C.-Bl. 37: 182, 1920; Galium trachyspermum var. miltorrhizum (Hance) T. Yamazaki., J. Jap. Bot. 66: 51, 1991.

Galium trachyspermum var. nudicarpum Honda, Bot. Mag. Tokyo 53: 385, 1939.

Korean name: Dung-geun-ne-ip-gal-kwi (둥근네잎갈퀴).

Plants annual or biennial herbs; rhizomes slender with a papery fibrous; commonly 10–18 cm tall. Stems erect or sometime decumbent at fruiting times, usually dichotomously branching, branched from tip of reddish fibrous roots; 0.1–0.2 mm diam. angles slender, 4-angled, glabrous. Leaves in whorls of 4, simple, exstipulated, 2 leaves are bigger than others; petiole less than 0.5 cm, subsessile in lower leaves, 1-veined, ovate-obovate or broadly lanceolate, 8–24 × 5–7 (8) mm, apex cuspidate with very short hyaline apiculum ca. 0.1 mm long, base attenuate, upper surface dull, glabrous, lower surface glabrous, inconspicuous scabrous glandular cell, rarely papillate on the upper and lower vein; margins entire, subrecurved or narrowly revolute, glabrous or with a few to several minute hairs on margins. Inflorescences terminal and/ or axillary, cymose to paniculate, congested to lax, cymes predominantly 2, 3-flowered or few to several flowered, peduncles erect, slender, quadrangular, glabrous, 0.3–1.2 cm at flowering, 1.5–3.0 cm in fruit, sometimes glandular cells, pedicel erect, capillary, slender, glabrous, 0.1–0.2 cm, bracts none. Flowers small, hermaphrodite, calyx absent; corolla yellowish green, rotate, 1.0–2.2 mm in diam., glabrous; lobes 4, petals ovate or oblong, apex acute, shortly attenuate and curved outward, margins entire; androecium with 4 stamens filament slender, adnate to the corolla, glabrous, 0.1–0.3 mm, anther ovate to elliptic, 0.1–0.2 mm. Ovary globose, 0.9–1.5 × 1.5–2.3 mm, composed of two mericarps, surface generally dull, glabrous; style 0.3–0.5 mm, two-branched, stigma capitate. Fruit schizocarp; mericarps 1.5–2.3 mm long, reniform, glabrous, rarely short papillate, purple to brown. Seeds reniform yellow to yellow-brown.

Flowering: Apr. to Sep.

Distribution: China, Japan, Korea.

Specimens examined: CHINA. Shijiazhuang, 23 Apr 1997, Deng & Fang 11002 (PE); Hengren County, 21 Jun 2001, Z. Hu 59 (PE).

KOREA. Gyeonggi-do: Pocheon-si, 27 Sep 2016, K.S. Jeong KS2016058 (KH); Chungcheongbuk-do: Danyang-gun, 13 Jun 2016, J.K. Shin Shin20160523 (KH); Jeollabuk-do: Namwon-si, 22 Aug 2012, K.S. Jeong et al. KS20120308 (KNU); Gyeongsangbuk-do: Gimcheon-si, 23 Jun 2012, K.S. Jeong et al. KS20120589 (KNU); Gyeongsangnam-do: Sancheong-gun, 2 Oct 1902, T. uchiyama s.n. (TI); Sancheong-gun, 20 Jul 2008, K.S. Jeong 200820589 (KNU).

Taxonomic note: Hance (1868) published a new species, Galium miltorrhizum Hance, characterized by leaves in whorls of 4 and glabrous ovaries and fruits, for the flora of China. However, Yamazaki (1991) treated this taxon as synonym of Galium trachyspermum var. nudicarpum Honda, which occurs in Japan, based on glabrous ovaries and mericarps. In addition, Yamazaki (1991) regarded Galium trachyspermum A. gray as a distinct species from G. bungei based on curved short antrorse hairs on their mericarps (Yamazaki, 1991). Meanwhile, Chen and Ehrendorfer (2011) treated Galium trachyspermum A. Gray as a variety of G. bungei, which has hooked hairs on the surface of its mericarp according to the classification of Cufodontis (1940).

The Dung-geun-ne-ip-gal-kwi which was first reported in Korea, is similar to varieties of G. bungei. in having whorls of 4 leaves and terminal or (and) axillary cymes. This taxon includes annual or perennial herbs that are all glabrous except for minute hairs on leaf margins. It is distinguished from other varieties of G. bungei recognized by Chen and Ehrendorfer (2011) by glabrous stems, ovaries and mericarps (Fig. 2). Additionally, this taxon differs drastically from G. bungei by having glabrous mericarps with mostly sparse indumentum of minute papillae. Galium bungei var. miltorrhizum can be easily distinguished from Galium bungei var. angustifolium (Loesener) Cufodontis by having ovate-obovates and broad lanceolate leaves with short petioles while Galium bungei var. angustifolium have narrow lanceolate leaves. We propose a new combination name for this unrecorded plant species, Galium bungei var. miltorrhizum (Hance) Jeong & Pak, according to Cufodontis (1940)'s work. This variety grows predominantly on mountain slopes in mixed forests and humid areas. It occurs with more than 30 individuals in a mixed forest on mountain slopes in Pocheon-si, Gyeonggi-do along with Pinus koraiensis Siebold & Zucc., Quercus variabilis Blume, Rubus oldhamii Miq., Galium dahuricum Turcz., Erythronium japonicum (Balrer) Decne., Primula sieboldii E.Morren. We also found a population of the species in forests with altitudes of c. 1,100 m in Sancheong-gun, Gyeongsangnam-do growing with Acer pseudosieboldianum (Pax) Kom., Sasa borealis (Hack.) Makino, G. dahuricum, Persicaria filiformis (Thunb.) Nakai ex Mori, Rubus crataegifolius Bunge. This given name for this taxon ‘Dung-geun-ne-ip-gal-kwi’ is based on shapes of leaves.

Fig. 2.

Phtographs of fruit. Galium bungei var. trachyspermum (A), Galium bungei var. angustifolium (B), Galium bungei var. miltorrhizum (C) (scale bars=1 mm).

Key to the Galium sect. Platygalium in Korea

1. Corolla white, leaves more than 3 cm long, 3-veined

2. Mericarps covered hooked hairs, plant less than 10 cm ·················································· G. kamtschaticum var. yakusimense (Masamune) Yamazaki (털둥근갈퀴)

2. Mericarps clothed pubescence or glabrous, plant more than 15 cm

3. Mericarps clothed pubescence (or glabrous), leaves oblong-lanceolate, apex acute ································· ········································ G. boreale L. (긴잎갈퀴)

3. Mericarps glabrous, leaves ovate, apex acuminate ····················· G. kinuta Nakai & Hara (민둥갈퀴)

4. Leaves linear-lanceolate, mericarps spreading uncinate trichomes ·· G. pogonanthum Franch. & Sav. (산갈퀴)

4. Leaves ovate-oblong, mericarps glabrous or short upward sub-appressed hairs

5. Mericarps covered curved short upward subappressed hairs, leaves 5–18 × 3–6 mm ··············· ···························································· G. bungei var. trachyspermum (A. Gray) Cufodontis (네잎갈퀴) 5. Mericarps glabrous (or rarely short papillate), leaves 8–17 × 4–7(8) mm ·············· G. bungei var. miltorrhizum (Hance) Jeong & Pak (둥근네잎갈퀴)

Acknowledgements

This study was supported by the Korea National Arboretum project ‘KNA1-1-13, 14-1.’

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Article information Continued

Fig. 1.

Galium bungei var. miltorrhizum habit with a inflorescence and leaves on stem. A. Flower. B. Fruit. C. Seed. D. Leaf. E. Leaves at node. F. Stem. WP - Whole plant.

Fig. 2.

Phtographs of fruit. Galium bungei var. trachyspermum (A), Galium bungei var. angustifolium (B), Galium bungei var. miltorrhizum (C) (scale bars=1 mm).