Plants erect, leafy, weak-stemmed. Leaves 1.5-3 × 6-11 cm; blade narrowly lanceolate to elliptic-spatulate on fertile shoots, broader on sterile shoots, glabrous, base cuneate, apex acute to rounded; petiole 2-4 cm. Umbels 3-8-flowered, bracteate. Flowers: tepals red to wine, spotted purplish brown, greenish at apex, narrowly spatulate, 3.5-4.5 cm, apex and margins of base slightly puberulent; pedicel 1.5-3 cm. Capsules globose, 1.3 × 1 cm, bluntish terminal portion with several spinose acuminations, each valve narrowly winged adaxially.

Flowering mid spring--early summer. Loose or sandy soils in shade to partially sunny, moist, disturbed sites; 0--100 m; introduced; Ala., Fla., Ga., La., Miss.; Brazil.

Alstroemeria pulchella is used as an outdoor ornamental in the warmer parts of the United States, where it has escaped and apparently become naturalized.