Ray flowers

The stem is erect, columnar at the base and branched at the top. The leaves are alternate, simple, rough, hairy, and ovate or heart-shaped with toothed edges. The heads are showy, with yellow to orange-yellow ray flowers and brown or dark reddish-brown disk flowers. Sunflowers begin to grow in early June, flower in August and September, and mature seed and die in late September. 

Flower heads occur alone or in groups at the ends of the stem and axillary branches. Each inflorescence is comprised of many small, yellow, tubular disk flowers in the center, surrounded by 10 to 20 sterile, yellow ray flowers, the ligules of which are often thought of as the petals (Figure 4.3). 

The number of ray flowers varies substantially among clones and individual inflorescences on a plant. In a representative clone, there was an average of 11.5 ray flowers per inflorescence however, this ranged from 9 to 14 flowers. 

Fig. 235.-—Capitulum o a composite Jerusalem artichoke Helianlhus tuberosus). A, lengthwise section of capitulum, X i B. ray flower, X 6 C, disk flower, cut lengthwise, X 6. (A after Baillon, B and C, Robbins.)...

Other distinguishing features Bases of mid-stem leaves partially clasping to auriculate. Ray flower hgules usually 1-3 mm long and 1.5-2.5 mm wide. 

Description Herbaceous annual or biennial, 30-90 cm tall, covered with long, white, raised hairs. Stems single or multiple, erect, branched. Lower stem leaves petiolate, tripartite-pinnatisect, 3-7 cm long cauUne leaves sessile, tripartite. Inflorescences 3-5-flowered capitula in panicles. Disk flowers yellow, punctate glandular ray flowers absent. Fruits obo-vate achenes, 2-2.25 mm long, olive-colored. 

Description Herbaceous annual or biennial plant with a thin vertical root. Stems single or few, 30-90 cm tall. Basal leaves petiolate, bi- or tripinnatisect, segments linear-lanceolate, apex acute middle cauline leaves smaller, sessile, segments narrow, linear upper cauline leaves deeply tri-lobed or entire. Inflorescences small capitula with 10-12 flowers, in a wide, nodding panicle involucral bracts brownish or pink-violet. Disc flowers yellow ray flowers absent. Fruits achenes, ca 0.6 mm long, ovate, flat with narrow ribs. 

Other distinguishing features 1-5 ray flowers occasionally present. Fruits usually not tuberculate. 

Description Herbaceous biennial, occasionally annual or perennial. Stems 30-90 cm taU. Leaves bi- or tripinnatisect basal leaves long-petiolate, segments linear-lanceolate cauline leaves short-petiolate. Inflorescence a compound umbel with 8-16 rays. Flowers small with 5 petals, white or pink. Fruit a 2-seeded schizocarp, brown, 3-5 mm long, 1-2 mm wide, sides flattened. 

Other distinguishing features Leaves glandular and slightly or densely hairy. Ray flowers sterile, 3-lobed. Achenes slightly... 

Description Herbaceous perennial, with long, woody rhizomes. Stems many, erect, 50-150 cm tall, branched in upper part. Leaves alternate, up to 20 cm long, 3-10 cm wide, bipinnatisect, elongate-ovate basal leaves petiolate stem leaves sessile lobes pinnatifid or dentate. Inflorescences capitula in flat-topped corymbs capitula semispherical, compact, 5-10 cm wide, with up to 200 flowers. Disc flowers yellow, 2-3 mm long, 5-lobed, peripheral flowers ca. 20, 3-4-lobed ray flowers absent. Fruits elongate achenes, often ribbed. 

The genus Echinacea has nine indigenous North American herbaceous perennial species. E. angustifolia, to 60 cm high leaves lanceolate flowers violet, ray florets as long as or less than the width of receptacle found in barrens, dry prairies Minnesota to Texas, west to eastern Colorado and Montana taproot wild dug little cultivation. E. pallida, to 120 cm, leaves lanceolate purple ray flowers to 9 cm in glades, prairies Wisconsin to Arkansas, eastern Texas to Iowa taproot wild dug cultivation in the United States and Europe. E. purpurea, to 90 cm, leaves ovate, coarsely toothed, basal ones often cordate root fibrous widely distributed in Midwestern United States entire market supply cultivated in Europe, North America, and Australia. ... 

LiGULE. Strap-shaped organ or body particularly, a strap-shaped corolla, as in the ray flowers of composites also a projection from... 

---