Helianthus devernii

Helianthus devernii is a North American species of flowering plant in the daisy family Asteraceae, known by the common name Red Rock sunflower. The perennial herbaceous plant is endemic to a portion of Nevada's Red Rock Canyon National Conservation Area measuring less than 1 acre (4,000 m2), where it grows in just two desert spring locations within the Mojave Desert. The plant reaches up to 102 cm (40 in) in height. Its leaves tend toward the grass-like shape, with a single prominent vein, and alternate up the stem. The flower heads feature 5-8 yellow apparent petals—ray florets—surrounding a larger number of disk florets; the seeds are 3.5–4.0 mm (0.14–0.16 in) long. H. devernii can be distinguished from the closely related Helianthus cusickii by its shorter ray petals and single-veined leaves, and genetic evidence indicates it is most closely related to Helianthus pumilus. With a total known population of 725 individuals in a very small area of distribution that is also subject to a ......read more on Wikipedia.