Western Sunflower

Description:

This perennial wildflower consists of a rosette of basal leaves up to 1½' across, from which a flowering stalk develops that is 2-4' tall. The blades of the basal leaves are 2-7" long and 1-3" across; they are oval to ovate in shape and their margins are smooth (entire) or serrulate with sparse small teeth. The blades of basal leaves usually have rounded bottom and blunt tips. Their upper blade surfaces are medium green and rough-textured, while their lower surfaces are light green. In addition to their central veins, the basal leaves have 1-2 pairs of lateral veins that originate from the bases of their blades. The slender petioles of the basal leaves are 1-4" long and light green. The flowering stalk is light green to greenish red and glabrous to hairy; it is mostly naked, except for 1-2 pairs of opposite leaves below and a few alternate leaves above. The blades of opposite or alternate leaves are 1-3" long and ¼-¾" across; they are lanceolate or elliptic in shape and usually smooth (entire) along their margins. The blades surfaces of these leaves are similar to those of the basal leaves, while their petioles are either absent or up to ½" long. The flowering stalk terminates in 1-12 flowerheads that are usually arranged in a panicle. The peduncles of these flowerheads are ½-6" long. Individual flowerheads are 1½-2½" across, consisting of 8-22 ray florets that surround numerous disk florets. The petaloid rays are yellow and oblong to elliptic in shape. The tiny disk florets have tubular corollas that are yellow and 5-lobed. Around the base of each flowerhead, there are several overlapping phyllaries (floral bracts). These phyllaries are 5-7 mm. long, light green, linear-lanceolate in shape, and ciliate along their margins. The blooming period occurs from mid-summer to early fall, lasting about 1 month for a colony of plants. Afterwards, the fertile disk florets are replaced by achenes about 3-4 mm. in length. These achenes are broadly oblongoid and somewhat flattened in shape; they have a pair of scale-like awns that are early-deciduous. The root system consists of a narrow taproot with shallow rhizomes. Vegetative colonies of plants are sometimes produced from these rhizomes.