Slender Sunflower

Perennials, 60–200 cm (taprooted). Stems (reddish or purplish) erect, hairy. Leaves cauline; all or mostly opposite; petioles 0–3 cm; blades (1- or 3-nerved) lanceolate to lance-ovate, 5–11 × 2–3.5 cm, bases cuneate, margins entire or serrate, abaxial faces hispid, gland-dotted. Heads 1–5. Peduncles 2.5–30 cm. Involucres hemispheric, 13–20 mm diam. Phyllaries 20–25, lanceolate, 4–8 × 1.5–3 mm, (margins ciliate) apices acute, abaxial faces hispidulous, gland-dotted. Paleae 8–9 mm, subentire to weakly 3-toothed (apices acute, ciliate, gland-dotted). Ray florets 13–21; laminae 15–25 mm (abaxial faces gland-dotted). Disc florets 50+; corollas 5–6 mm, lobes reddish; anthers reddish brown, appendages yellow or dull orange (style branches yellow ). Cypselae 3–4 mm, glabrate; pappi of 2 aristate scales 2.5–3 mm. 2n = 34.

Helianthus gracilentus is a species of sunflower known by the common name slender sunflower. It is native to central and southern California (from Napa County to San Diego County) and Baja California, where it is a member of the dry wildfire-prone chaparral ecosystem.

Helianthus gracilentus is a perennial herb growing from a thick taproot to heights anywhere between one half and two meters (20-60 inches). The lance-shaped, pointed leaves are smooth-edged or slightly toothed and up to about 11 centimeters (4.4 inches) long. The long, slender stems and foliage are covered in rough hairs. The inflorescence bears flower heads with an array of short, hairy phyllaries behind a thick center of yellow to red-brown disc florets. The golden ray florets around the edge are one to three centimeters (0.4-1.2 inches) long.