Helianthus petiolaris ssp. fallax
Family: Asteraceae (A Utah Flora – Compositae) – Sunflower Family
Annual herbs; stems 2” to 3.9' (0.5 to 12 dm) tall
Leaves: mainly alternate; simple; 0.4” to 3.2” (1 to 8 cm) long, 0.16” to 1.2” (4 to 30 mm) wide; has hairs
Flowers: yellow ray flowers; disk 0.4” to 1” (10 to 25 mm) wide; disk corolla lobes purplish; perfect; fertile; flower head appears to be a single flower, but is composed of several flowers (a composite)
Pollinators: bees and flies
Fruits: achene – 1 seeded with hard shell
Blooms in Arches National Park: April, May, June, July, August, September, October, early November
Habitat in Arches National Park: riparian, desert shrub, grassland and pinyon-juniper communities
Location seen: park road north of Courthouse Towers, main park road between Delicate Arch turnoff and Fiery Furnace, park road in Salt Valley
Other: The genus name, “Helianthus”, is derived from the Greek words “helios”, which means "sun" and “anthos”, which means "flower" and refers to the flower's habit of turning with the sun. The species name, “petiolaris”, means “remarkable leaf stalk, with conspicuous petioles; the subspecies name, “fallax”, is Latin for “deceptive”.
This family is the most advanced and complex of the dicots. The family is rich in oils and resins and is found in every part of the world, but is infrequent in the tropical rainforest. Aquatic or semi-aquatic species are also uncommon.