Little Sunflower

Perennials, 30–100 cm (taproots slightly thickened). Stems erect, hispid or strigose. Leaves cauline; opposite; petioles 0.4–3 cm; blades (ashy green, usually 3-nerved from bases) lanceolate to ovate, 4–15 × 1–5 cm, bases ± cuneate to truncate, margins entire or serrate, faces strigoso-hispid, gland-dotted. Heads 1–6. Peduncles 0.5–5.5 cm. Involucres cylindric, 7–14 mm diam. Phyllaries 15–25 (loosely appressed), lanceolate to ovate, 3.5–7.5 × 2–3.5 mm, apices acute to acuminate, abaxial faces ± hispid or strigose (hairs whitish), gland-dotted. Paleae 7–8 mm, entire or ± 3-toothed (apices acute to acuminate, hispid). Ray florets 8–13; laminae 15–20 mm (abaxial faces gland-dotted). Disc florets 30+: corollas 5–6 mm, lobes yellow; anthers dark brown to black, appendages dark. Cypselae 3–4 mm, sparsely hairy; pappi of 2 aristate scales 4–4.5 mm plus 0–4 deltate scales 0.5–1 mm. 2n = 34.

Helianthus pumilus is a North American species of sunflower known by the common name little sunflower or bush sunflower. It is found in the western United States, primarily the Rocky Mountain region of Montana, Wyoming, and Colorado, with a few isolated populations in Utah and Idaho.

Helianthus pumilus grows on dry rocky soil in the mountains and nearby plains. It is a perennial herb up to 100 cm (40 inches) tall. One plant usually produces 1-6 flower heads, each containing 8-13 yellow ray florets surrounding 30 or more yellow or brown disc florets.