Plains Onion

Bulbs 2–20+, without basal bulbels, 1–2.5 × 1.2–2.8 cm; outer coats enclosing 1 or more bulbs, dark brown, reticulate, cells coarse-meshed, open, fibrous; inner coats whitish, cells regular, vertically elongate, walls not sinuous. Leaves persistent, green at anthesis, 3–5, sheathing; blade solid, flat, channeled, 8–30 cm × 1–2(–3) mm, margins entire. Scape persistent, solitary, erect, ± terete, 10–20 cm × 1–3 mm. Umbel persistent, erect, loose, 5–25-flowered, hemispheric-globose, bulbils unknown; spathe bracts persistent, 2–3, 3–7-veined, ovate, ± equal, apex acuminate. Flowers urceolate, 7–10 mm; tepals erect, white or pale pink with deep pink midribs to deep rose, lanceolate, ± equal, becoming callous-keeled and permanently investing capsule, margins entire, apex obtuse or acute; stamens included; anthers yellow or purple; pollen yellow; ovary crestless; style linear, ± equaling stamens; stigma capitate, unlobed or obscurely lobed; pedicel 3–17 mm, ± 2 times perianth at anthesis, elongating in fruit. Seed coat dull or shining; cells minutely roughened.

Allium perdulce, the Plains onion, is a plant species native to the central part of the United States and cultivated as an ornamental elsewhere. It has been found in Texas, New Mexico, Oklahoma, Kansas, Nebraska, South Dakota, and one county in western Iowa (Woodbury County).

The species name, "perdulce", is neo Latin meaning "especially sweet". This is a reference to the scent of the flowers which resembles hyacinths.

Allium perdulceproduces 2-20 bulbs, each up to 3 cm (1.2 inches) in diameter. Flowers are urn-shaped, up to 10 mm (0.4 inches) across; tepals deep rose to purple (except in var. sperryi; see below); pollen yellow.

Two varieties are recognized:

Allium perdulce var. perdulce Allium perdulce var. sperryi Ownbey

Var. sperryi is a color variant known only from western Texas in the trans-Pecos region. It has white to pale pink flowers instead of the more widespread deep rose to purple.