Astragalus preussii (common name - Preuss" milkvetch) is an annual or perennial plant in the legume family (Fabaceae) found in the Colorado Plateau and Canyonlands region of the southwestern United States. :121Growth pattern. It is an annual or perennial plant from 4 to 15 inches (10 to 38 cm) tall, growing upright from a woody base. :121Leaves and stems. It has compound pinnate leaves from 1 1-2 to 15 inches (3. 8 to 38. 1 cm) long, with 7-25 3-4 inch (1. 9 cm), elliptic leaflets. :121Inflorescence and fruit. It blooms from March to June. :121 The inflorescence has 3-22 flowers per stalk, with a small, green, 5-lobed calyx around a tublular set of white to pink to purple petals, 3-4 inch (1. 9 cm) long. :121 When dried, 3-4 inch (1. 9 cm) seed pods are papery or leathery, elliptical, and are either smooth or covered with soft hairs. :121Habitat and range. It only grows in soils containing Selenium. :121Ecological and human interactions. It is named after Charles Preuss. :121