Arabis erecta Y.Y. Kim & C.G. Jang, 2016

Kim, Yoon-Young, Jang, Changgee, Ji, Seong-Jin, Oh, Sang Heon, Na, Nu-Ree, Leem, Hyosun, Kim, Tae-Weon, Lee, Woo-Rak & Lim, Yong Pyo, 2016, Arabis erecta (Brassicaceae), a new species from Republic of Korea, Phytotaxa 268 (4), pp. 279-285 : 280

Arabis erecta Y.Y. Kim & C.G. Jang , sp. nov. ( Figs. 1 , 2 ).

Type:— Republic of Korea. Gyeongsangbuk-do: Iga-ri, Cheongha-myeon, Pohang-si, 5 m, 36°11 ′ 22.14 ′′ N, 129°22 ′ 37.66 ′′ E, 16 July 2015. Y. Y. Kim & C. G. Jang 20150716-001 (Holotype KNH!).

Herbs, perennial, 10–40 cm tall, rhizomatous, pilose. Taproots slightly fleshy, persistent after seed dispersal. Rhizomes condensed. Stems simple or branched at base, erect to ascending, non-gemmiferous in cauline axil, trichomes forked or 3–4-rayed stellate. Leaves basal and cauline; basal leaves rosulate, simple, fleshy, glossy, glabrous except on margin and midvein, 3–12 cm long, withered after anthesis, midvein persistent; petiole 1–5 cm long, winged at margin; leaf blades spatulate, oblanceolate or obovate, 1–10 × 0.5–2.5 cm, base attenuate, margin entire or denticulate, apex rounded; trichomes forked or 3–4-rayed stellate on margin and midvein; cauline leaves alternate, simple, fleshy, glossy, glabrous except on margin and midvein; petiole sessile; leaf blade ovate to ovate–lanceolate, 1–7 × 0.5–5 cm, base auriculate, margin entire or dentate, apex rounded; trichomes similar to those on basal leaves. Inflorescence a raceme, ebracteate, condensed, many flowers simultaneously open; rachis green to purple, with forked or 3–4-rayed stellate trichomes. Flowers symmetrical. Pedicel green to purple, cylindrical, glabrous, 2–7 mm long, 0.7–0.8 mm diam. Receptacle ca. 1 mm diam. Sepals 4, green to purple, concave, glabrous; median ones ovately lanceolate, 3.5–4 × 1.4– 1.8 mm, apiculate in apex; lateral ones elliptical-ovate, 3.2–3.6 × 1.4–1.8 mm, apiculate and incurved in apex. Petals 4, white, oblanceolate, 6–8 × 2–2.3 mm, apex truncate or rounded; basal claw green, attenuate, gradually narrowed, entire in margin. Stamens 6, tetradynamous, superior ones 4.5–5.5 mm., inferior ones 4–4.8 mm; filaments white but green at base, cylindrical, gradually narrowing upward, superior ones 3.5–4.5 × 0.5 mm, inferior ones 3–3.8 × 0.5 mm; anthers yellow or purple, ovate, ca. 1.3–1.5 × 0.7–0.8 mm, apex apiculate. Nectar glands 4, median and lateral gland confluent, L-shaped; median glands 4, each separate, 0.15 × 0.3 × 0.2 mm; lateral glands 4, each separate, 0.3 × 0.3 × 0.45 mm. Ovary green to purple, cylindrical, glabrous, 3.5–4.3 mm long, 0.5–0.55 mm diam., midrib opaque, smooth; ovules 15–25 per locule; style inflated, 0.3–0.4 mm long, 0.5 mm diam.; stigma capitate, ca. 0.5 mm diam. Fruiting pedicels green to purple, erect, appressed to rachis, stout, glabrous, cylindrical, 2–8 mm long, 1 mm diam.; receptacle ca. 1.3 mm diam.; gynophore 0.3 mm long, 1 mm diam. Siliques green to purple, erect, appressed to rachis, cylindrical, stout, smooth, glabrous, 2.5–5 cm long, ca. 1.8 mm diam.; midrib grooved; valves glabrous; styles condensed, stubby, rounded, 0.2–0.3 mm. Seeds uniseriate, unseparated, brown, oval or suborbicular, flat, 1.2–1.6 × 0.9–1.2 mm, winged; wing dark brown, 0.1–0.2 mm; seed coat reticulate.

Korean name:—Seon-gaet-jang-dae (Ḩṋğ¨).

Distribution and habitat:— Republic of Korea (Prov. Gyeongsangbuk-do). Seasides (usually sandy soils, rarely granite soils or rock crevices) ( Fig. 3 ).

Phenology:—Flowering April–May, fruiting July–May.

Ecology:— Arabis erecta is found in the north-northeast shady coast of Pohang-si, Yeongdeok-gun and Uljin-gun, Gyeongsangbuk-do. Its habitat is dominated by Pinus thunbergii Parl. , with Tetragonia tetragonioides (Pall.) Kuntze , Spergularia marina (L.) Besser, Sedum takesimense Nakai , Cnidium japonicum Miq. , Calystegia soldanella (L.) Roem. & Schult., Lathyrus japonicus (Willd.) DC. , Linaria japonica Miq. , Achillea alpina L., Artemisia scoparia Waldst. & Kit. , Aster spathulifolius Maxim. , Carex laticeps C.B.Clarke ex Franch. , and Luzula capitata (Miq. ex Franch. & Sav.) Kom. in the herbaceous layer.

Etymology:—The specific epithet of the new species refers to the “stems usually erect, and fruiting pedicels and siliques appressed to rachis”.

Additional specimens examined:— Republic of Korea. Gyeongsangbuk-do: Woncheon-ri Namjeong-myeon Yeongdeok-gun, 19 May 2010. Chung G. Y. et al. ANH-000010709, ANH-000011636 ( ANH!) ; Iga-ri, Cheongha-myeon, Pohang-si , ele. 5 m, 36°11’22.14”N, 129°22’37.66”E, 6 Jan. 2016. Y. Y. Kim 20160106-001—003 (Paratypes KNH!) ; Giseong-ri, Giseong-myeon, Uljin-gun , ele. 6 m, 36°48’23.80”N, 129°27’27.67”E, 7 Jan. 2016. Y. Y. Kim 20160107-001—003 (Paratypes KNH!) .

Comparison:—This plant is similar to A. stelleri DC. and A. takesimana Nakai in its general vegetative and floral morphology. However, the new species is distinguished by its glabrous leaves surface, not inflated receptacle, 4 nectar glands (median and lateral glands confluent, L-shaped), and fruiting pedicels and siliques appressed to the rachis ( Table 1).

Figures

FIGURE 1. Images of Arabis erecta Y.Y. Kim & C.G. Jang. A. Habit. B. Root and rhizome. C. Stem. D. Leaf base. E. Leaf margin. F. Flowers. G. Petal. H. Fruits. I. Fruiting pedicel. J. Fruiting styles (a: adaxial view, b: lateral view). K. Arrangement of seeds (wetted). L. Seeds (dried). Photographs by Yoon-Young Kim.

FIGURE 2. Illustrations of Arabis erecta Y.Y. Kim & C.G. Jang. A. Habit. B. Stem. C. Leaf margin. D. Sepals (a: median, b: lateral). E. Petals. F. Stamens. G. Receptacle, nectar glans and ovary. H. Fruit. I. Seed. Illustrations by Hyosun Leem & Yoon-Young Kim.

FIGURE 3. Distribution map of Arabis erecta Y.Y. Kim & C.G. Jang (right: zoomed in area in Google Maps of boxed area on left). Illustrations by Yoon-Young Kim.