黃花月見草

Oenothera glazioviana is not a native plant to any area in the usual sense, having originated via hybridization between two cultivated or naturalized species in a garden in Europe. It was introduced into the horticultural trade as early as 1860, grown for its particularly large, attractive flowers, and has become very widely naturalized.

Herbs erect, biennial to short-lived perennial, with basal rosette. Stems 50-150 cm tall, usually branched throughout, densely to very sparsely strigillose, with long suberect red pustulate-based hairs, and glandular hairs on inflorescence. Leaves dark to bright green, with inconspicuous veins, surface often crinkled, villous to strigillose, sessile to shortly petiolate; rosette blade 13-30 × 3-5 cm; cauline blade narrowly elliptic to lanceolate or oblanceolate, 5-15 × 2.5-4 cm, base attenuate to narrowly cuneate, margin remotely dentate, usually undulate toward base, apex acute to subobtuse. Inflorescence a dense unbranched spike. Flowers open near sunset; floral tube 3.5-5 cm. Sepals 2.8-4.5 cm, with free tips 5-8 mm, apical, erect or spreading. Petals yellow, fading to reddish orange, 3.5-5 cm. Anthers 1-1.2 cm; pollen ca. 50% fertile. Ovary densely to moderately villous, with long red pustulate-based hairs and dense glandular hairs; stigma elevated above anthers. Capsules green, narrowly lanceoloid, 2-3.5 cm, sessile. Seeds in two rows per locule, brown to dark brown, 1.3-2 mm, irregularly pitted, up to ca. 50% abortive. Fl. Jul-Sep(-Oct), fr. Aug-Oct. 2n = 14, permanent translocation heterozygote; self-compatible, usually outcrossing.

Plants usually biennial, forming a rosette, erect, with simple or much-branched main stem, 1-12 dm tall. Plants strigillose and coarsely erect villous, some to many of the hairs with a reddish-purple pustulate base, the inflorescence mixed villous and glandular-pubescent. Rosette leaves narrowly lanceolate to oblanceolate, 13-30 x 3-5 cm; cauline leaves narrowly elliptic to lanceolate, narrowed to the petiole, the uppermost sessile, 5-12 x 2.5-4 cm, bracts lanceolate to narrowly ovate, 1-3(-5) x 0.7-3.2 cm; all leaves undulate at the margins and sinuate-toothed to serrulate, sometimes reddish along the midrib. Inflorescence simple or branched: Floral tube 3.5-5 cm long. Sepals 2.8-4.2 cm long, red-striped along the midrib; sepal tips 5-8 mm long, spreading. Petals yellow, broadly obcordate, 3.5-5 cm long. Style 5-8 cm long, the stigma held above the anthers at anthesis. Capsule narrowly lanceolate in outline, 2-3 x 0.5-0.6 cm, green with a red median stripe on each valve, and with reddish-purple pustulate based hairs. Seeds prismatic, 1.3-2 x 1-1.5 mm. Self-compatible, but mostly outcrossing. Gametic chromosome number, n = 7 (ring of 12 and 1 bivalent at meiotic metaphase I).

Anhui, Guizhou, Hebei, Henan, Hunan, Jiangsu, Jiangxi, Jilin, Shaanxi, Sichuan, Yunnan, Zhejiang [Afghanistan, India, Japan, Pakistan, Russia; Africa, SW Asia, Australia, Europe, North and South America, Pacific islands (New Zealand)].

Distribution: Widely distributed, but not known as a native plant anywhere, now naturalized on all continents except Antarctica; apparently not extensively naturalized in Pakistan at present.

Open disturbed sites such as roadsides, gardens, fallow fields, and along railroad tracks; near sea level to 800 m.

This attractive species is a common garden plant. In fact according to Raven et al. (Syst. Bot. 4: 248. 1979), O. glazioviana apparently originated through hybridization in a European garden between two species of sect. Oenothera subsect. Euoenothera prior to 1860, when it is known to have been in the horticultural trade. The cross probably involved O. biennis Linn. as one parent and O. grandiflora L'HJr. ex Ait. or O. elata H.B.K. as the other. The possibility also exists that the two parents were O. grandiflora and O. elata. Stewart (l.c. 508) lists O. biennis as a garden plant in Pakistan, but we have not seen any specimens; the plants to which he refers are apparently all O. glazioviana. Oenothera biennis is sharply distinct in its smaller flowers (10-25 mm long) and the stigma which is surrounded by the anthers at anthesis. Fl. Per.: Jun-Sep.

Oenothera erythrosepala (Borbás) Borbás; Onagra erythrosepala Borbás.

O. lamarckiana auct. mult., non SJringe in DC., Prodr. 3: 47. 1828; R. R. Stewart, Ann. Cat. Vasc. Pl. W. Pak. & Kashm. 508. 1972; O. erythrosepala Borbas, Magyar Bot. Lapok 2: 245. 1903; Raven in Tutin et al., Fl. Eur. 2: 306. 1968; Dietrich, Ann. Missouri Bot. Gard. 64: 616. 1978.