Melampyrum koreanum K.-J. Kim & S.-M. Yun

Kim, Ki-Joong & Yun, Seok-Min, 2012, A new species of Melampyrum (Orobanchaceae) from Southern Korea, Phytotaxa 42, pp. 48-50 : 48-50

Melampyrum koreanum K.-J. Kim & S.-M. Yun , sp. nov. Fig. 1 A–K

M. roseum Maxim. similis sed corolla tubus et stylus 25–30 mm longus differt.

TYPE:― KOREA, Keungsangnam-do : Tongyoung-shi , Hansan-myeon, Somaemuldo, Oct. 17, 2008. K.-J. Kim and Seok Min Yun 2008-1561, (holotype, KUS; isotype, 7 sheets, KUS, MO, NIBR) .

Herbs, annuals, hemiparasites; glabrous or pubescent; stems erect, 50–90 cm tall, with many opposite branches. Leaves opposite, glabrous; lower leaves lanceolate, 1.0– 1.5 cm wide, 4.0– 5.5 cm long, petiole 0.4– 0.9 cm long, mid-vein distinct on the lower surface, lateral veins opaque, base acute, tip acute, margin entire; upper leaves lanceolate, 0.5–1.0 cm wide, 2.0–3.0 cm long, petiole 2–4 mm long, mid-vein distinct on the lower surface, lateral veins opaque, base acute, tip acute, margin entire; bract-like leaves triangular-lanceolate, one or two pairs with setose teeth at base, 4–6 mm wide at base, 10–15 mm long, petiole 2–4 mm long, midvein distinct on the lower surface, base truncate, tip acute-acuminate, sometimes upper leaves and bract-like leaves are indistinctive. Flowers solitary in axils of upper bract-like leaves or congregated into terminal spikes; peduncles 1–2 mm long; calyx tubular-campanulate, 2–3 mm in diameter, 3–5 mm long; lobes 4 with setose tip, upper 2 lobes slightly larger than lower lobes, glabrous or pubescent; corolla tube linear-cylindrical, 2 mm in diameter, 25–30 mm long, slender, expanded upward; limb dilated, bilabiate; upper lip galeate, laterally compressed, with narrow, recurved margin; lower lip slightly longer than upper lip, patent, base 2- plicate, apex 3-lobed; stamens 4, didynamous, enclosed by galea, 10–14 mm long; anthers connivent, held almost vertically in throat, bilocular, thecae with sharply pointed appendages at base; pistil with bilocular ovary; style filiform, curved tip, 25–30 mm long, stigma slightly capitate, entire; ovules 2 per locule. Fruit a capsule, oblong, surface with reticulate veins, ovoid with pointed tip, 7 mm wide, 8–10 mm long, slightly compressed, straight or oblique, loculicidal, apex obtuse or tapered; seeds 3–4, oblong.

Distribution and habitat: ― Melampyrum koreanum is known only from the small island Somaemul-do, of Kyeongsangnam-do, South Korea. It grows on open mountain slopes in Pinus thunbergii forest on brown soil. This species is only known from its type locality and only 60 individuals occur in a small area. Therefore, we think that the habitat of this remarkable species should be conserved.

Additional specimens examined: ―No previous collections available.

Comparison: ― Melampyrum koreanum is closely related to the M. roseum complex (Nakai, 1917; Hong et al., 1998; Yamazaki, 1989; 1993). However, Melampyrum koreanum differs from M. roseum notably by having a longer, more slender corolla tube, longer style, larger capsules with more seeds, fewer setaceous teeth on the bract-like leaves, as well as being more branched and taller. The corolla length and style length of M. roseum are usually 10–15 mm. We examined numerous herbarium specimens of Melampyrum from K, KUN, IBSC, MO, PE and TI. None of the described species of Melampyrum has a corolla tube longer than 20 mm. Therefore, we believe that M. koreanum has the longest corolla tube and style of any Melampyrum species. We observed pollinators from the natural locality of M. koreanum for more than one hour. Hawkmoths of family Sphingidae were the only insects attracted to the M. koreanum flowers. Therefore, we believe that the long corolla tube and style are the adaptive traits to the pollinator. In contrast, the flowers of M. roseum complex are usually visited by bees.

Etymology: ―The specific epithet of the new species refers to the endemism in Korea.

Phenology: ―Flowering in September to late October; fruiting in early October to early November.

Figures

FIGURE 1. Melampyrum koreanum K.-J. Kim & S.-M. Yun. A. Flowering branches. B. Upper corolla lobes and stamens. C. Developing flowers. D. Mature flower. E. Calyx and style. F. Lower leaf. G–H. Upper bract-like leaves. I–J. Capsules. K. Seeds. All scale bars are 1 cm. Drawn from the holotype K.-J. Kim and Seok Min Yun 2008-1561(KUS).