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Helianthus niveus ssp. tephrodes is an annual herb from a stout taproot. Plants are somewhat shrubby and are white sericeous-villous, leaves are alternate, deltoid, entire. Heads are solitary on long peduncles. The ray flowers are yellow and the disc flowers are purple. The plants are intermediate between two other subspecies, H. niveus ssp canescens and the typical subspecies. H. niveus shows some similarities to Viguera, but is clearly a Helianthus, and is regarded as the most primitive of the genus Helianthus, and may have given rise to all the North American sunflowers. Hybrids have been secured between H. niveus and all three sections of North American sunflowers.
H. niveus ssp. tephrodes grows near Yuma, Arizona, in the extreme southwestern corner of the state and south into Sonora, Mexico. They are found in shifting sand dunes, and flower between September and May. Threats to plants are habitat degradation due to off road vehicle use.
Desert Botanical Garden has approximately 5,000 field-collected seeds in storage and over 1,000 seeds produced in cultivation. Germination experiments were conducted in 1991 and 1992, with final percentages ranging from 0-40%. Plants were grown out in a sand bed containing sand imported from Yuma, grown to maturity, and seeds were harvested.
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