23. Allium fistulosum Linnaeus, Sp. Pl. 1: 301. 1753.
Welsh onion, Japanese bunching onion
Bulbs 2–12+, borne on short rhizome, cylindric, 2–5 × 1–2.5 cm; outer coats enclosing 1 or more bulbs, white to light brown, membranous, without reticulation; inner coats white, cells obscure, quadrate. Leaves persistent, 2–6, sheathing lower 1/4–1/3 of scape; blade terete, fistulose, 10–40 cm × 10–25 mm. Scape persistent, solitary, erect, fistulose, inflated in middle, tapering to umbel, (12–)15–70 cm × 8–25 mm. Umbel persistent, erect, compact, 50–100-flowered, globose to ovoid, bulbils unknown; spathe bracts persistent, 1–2, 1–3-veined, ovate, ± equal, apex acute. Flowers narrowly campanulate to urceolate, 6–9 mm; tepals erect, yellowish white, withering in fruit, margins entire, apex acute, outer lanceolate, inner narrowly ovate, unequal; stamens long-exserted; anthers white to yellow; pollen white; ovary crestless; style linear, equaling stamens; stigma capitate, obscurely 3-lobed; pedicel 10–30 mm. Seed coat shining; cells 4–6-angled, ± rectangular.
Flowering Jul--Aug. Disturbed areas; introduced; N.W.T.; Alaska; cultivated in Europe, Asia.
Allium fistulosum is cultivated in Europe and Asia. It is reported to have escaped in Alaska and is established near the north end of Great Slave Lake. The species is to be expected elsewhere in Canada and the northern United States.