How to Grow and Care for Holocarpha

Yellowflower tarweed (Holocarpha virgata) is an annual herbaceous flowering plant whose foliage smells like turpentine. The entire plant is sticky to the touch. It attracts bees, birds, and small mammals but as it matures, the unpleasant scent repels livestock and deer. Also called virgate tarweed or pit gland tarweed. It blooms yellow flowers from spring to fall.

Holocarpha heermannii is an annual herb growing mostly erect from 20 cm to over 1.006 m in height. The stem is densely glandular and coated in short and long hairs. The leaves are up to 10 cm long near the base of the plant and those along the stem are smaller. The inflorescence is a spreading array of branches bearing clusters of flower heads. Each flower head is lined with phyllaries which are coated in large bulbous resin glands. They are hairy and sticky in texture. The head contains many yellow disc florets surrounded by three to 10 golden yellow ray florets. The ray and fertile disc florets produce achenes of different shapes.

Santa cruz tarplant is characterized by a tall, robust stature, with stems that can reach over a meter in height. Its vibrant yellow flowers bloom in clustered heads, drawing pollinators to their sun-like radiance. The plant thrives in open grasslands, adapted to well-drained soils, where it stands out against a backdrop of greenery with its distinctive long, narrow leaves that clasp the stem. Notoriously resilient, santa cruz tarplant has evolved to endure the variable moisture and fire cycles of its native habitat.