European Wallflower

A very plymorphic and complex species, often split into a number of infra specific ranks of uncertain status.

This is a highly variable species, and many of the Himalayan records, including those from Bhutan, Nepal, and Sikkim, belong to Erysimum benthamii. The record of E. odoratum Ehrhart in FRPS is likely based on misidentified plants of E. hieraciifolium. The present authors have seen no material of the strictly European E. odoratum from China.

Biennial to perennating herbs (sometimes a year old plant looks like annual), 30-60 (-90) cm tall, erect, appressedly hairy with 2-4-parted hairs; stem often simple, subangular, rarely branched. Basal leaves rosulate, very variable, elliptic-oblong to oblanceolate, stalked, 40-60 (-80) mm long, 3-10 mm broad, sparsely toothed to subentire; cauline leaves ± similar to basal leaves or linear, subsessile or sessile. Racemes 20-60-flowered, up to 40 cm long in fruit. Flowers c. 10 mm across, yellow; pedicels (5-) 6-10 mm long, ascending. Sepals 5-6 mm long. Petals 8-10 mm long, 3-3.5 mm broad, long-clawed. Stamens c. 5:7 mm long; anthers c. 2 mm long. Siliquae linear-terete, erect, (20-) 30-60 (-70) mm long, 1.5 mm broad, appressedly hairy; valves with a distinct mid-rib; style 0.5-1.5 mm long with capitate, bilobed stigma; seeds c. 1 (-1.5) mm long, oblong.

Herbs biennial, (10-)30-90(-110) cm tall. Trichomes primarily 3- or 4-fid, malpighiaceous ones primarily on stem and pedicels. Stems erect, often branched above, slightly ribbed. Basal leaves rosulate, withered by fruiting; petiole 1-4 cm; leaf blade elliptic-oblong or oblanceolate, (1-)2-6(-8) cm × (0.3-)5-10 mm, base cuneate, margin entire or obscurely denticulate, apex acute. Cauline leaves sessile or subsessile; leaf blade linear or elliptic-linear, entire or obscurely denticulate. Racemes corymbose, densely flowered, ebracteate, elongated considerably in fruit. Fruiting pedicels suberect or ascending, (3-)4-8(-10) mm, slender, narrower than fruit, subappressed to rachis. Sepals oblong, 4-7 × 1-1.5 mm, not saccate. Petals yellow, obovate, (6-)7-9(-10) × 2-3 mm, apex rounded; claw distinct, subequaling sepals. Filaments yellow, 4-6 mm; anthers oblong, 1.5-2 mm. Ovules 40-60 per ovary. Fruit linear, 4-angled, (1-)1.5-2.5(-4) cm × 1-1.3 mm, somewhat torulose, erect and often appressed to rachis, straight; valves with a distinct midvein, outside with 3- or 4-forked trichomes and fewer malpighiaceous ones, inside glabrous or rarely sparsely pubescent; style slender, 0.5-2 mm, cylindric; stigma capitate, entire. Seeds oblong, 1-1.5 × 0.4-0.6 mm. Fl. May-Aug, fr. Jun-Sep. 2n = 16.

Europe, Caucasus, C. Asia, Himalaya, Mongolia, Siberia.

Distribution: Europe and Temp. Asia.

Heilongjiang, Liaoning, Nei Mongol, Xinjiang, Xizang [Kashmir, Kazakhstan, Mongolia, Pakistan, Russia, Tajikistan, Uzbekistan; Europe; introduced in North America].

1600-3800 m

Fl. Per.: May-July.

Moist areas, grasslands; 2100-3800 m.

Erysimum afghanicum Kitamura; E. eseptatum Z. X. An.