Flowerheads have both ray flowers and disk flowers
Ray flowers have yellow or orange rays which are at least ca 5 mm long
Disk flowers are arranged in one or more distinctive heads
Guide to Identify Presented Species of this group
FLOWERHEADS 2 OR MORE ALMOST ALL LEAVES OPPOSITE
Arnica – Arnica Perennials with mostly erect, simple stems. Mostly in the mountains.
Flowerheads yellow with about 10-20 broad ray flowers. The bracts mostly equal.
Leaves mostly few, simple, opposite in pairs, entire or toothed.
FLOWERHEADS 2 OR MORE, THE BRACTS STICKY OR GLANDULAR LEAVES SIMPLE AND THE UPPER ALTERNATE
Grindelia – Gumweed Plants 20-90 cm tall, hairless or glandular hairy. Moist to dry, open places.
Flowerheads yellow, 2-3 cm wide, with sticky, backward curled involucral bracts.
Leaves alternate, oblong, 1-20 mm long, 5-20 mm wide, entire or toothed.
FLOWERHEADS 2 OR MORE, THE BRACTS NOT STICKY LEAVES SIMPLE AND THE UPPER ALTERNATE
Helianthus – Sunflower Annuals or perennials up to 200 cm tall. Open, dry or moist areas, roadsides.
Flowerheads few to several, with yellow rays around a button of disk flowers.
Leaves alternate, triangular to narrowly lanceolate, with rough hairs and stalks.
Senecio – Groundsel Perennials with erect, mostly simple and hairless stems. Mostly in moist areas.
Flowerheads with few rays, often with spaces between. Bracts in one equal row.
Leaves alternate, sometimes all basal, entire to variously toothed or divided.
FLOWERHEADS 2 OR MORE LEAVES ALTERNATE, CUT INTO DEEP OR NARROW SEGMENTS
Ratibida columnifera – Prairie Coneflower Stems 30-120 cm tall, usually several from base. Prairies, disturbed ground.
Flowerheads with 3-7 rays, the disc cluster raised to a tall, cylindrical column.
Leaves alternate, lance-shaped, deeply pinnately cut into 5-9 segments.
