Asteraceae: Senecio crassulus

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Family Name

Asteraceae

Common Name

Thickleaf ragwort

Description

Senecio crassulus is a perennial herb growing 30 to 60 cm tall from a fibrous root system. The stems are erect, smooth to slightly hairy, and succulent in texture. The plant flowers from July through September. Leaves are alternate, simple, succulent, lanceolate to narrowly ovate, 3 to 8 cm long and 1 to 3 cm wide, with entire margins. The upper leaf surface is smooth and bluish green, the lower surface paler and glabrous. Petioles are short, about 1 to 2 cm long. The inflorescence is a corymb or loose cluster of yellow composite flowers about 10 to 15 mm in diameter. Each flower head is surrounded by narrow, lanceolate involucral bracts about 3 to 5 mm long and 0.5 to 1 mm wide, free and arranged in several series. The corolla of ray florets has a single strap-shaped petal about 7 to 10 mm long and 2 to 3 mm wide, free and spreading, while disc florets have tubular corollas about 5 to 7 mm long. Stamens number five per floret, with filaments fused into a tube around the style and anthers about 1 to 2 mm long. The pistil is single, about 1 to 2 mm long, a style about 2 to 3 mm long, and a bifid stigma. The fruit is a small achene about 2 to 3 mm long that matures from August to October, topped with a pappus of fine hairs for wind dispersal. Thickleaf ragwort is native to South Dakota, found in dry open sites, rocky slopes, and prairies mainly in the western regions of the state.

Additional Notes

Thickleaf ragwort plays an ecological role in native dryland habitats, attracting pollinators and aiding soil stabilization.

Horticulture Notes

Seed collection: Usually from September to October when the achenes mature and begin to disperse.

Germination: Seeds require well-drained soil and light exposure; moist conditions aid germination but overwatering should be avoided.

Vegetative Propagation: Propagated  by stem cuttings.

Soils: Prefers sandy or rocky, well-drained soils typical of arid environments.

Light: Thrives in full sun.

Water: Very drought tolerant; minimal watering required.