Trifolium macrocephalum aka Large Head Clover

Trifolium macrocephalum belongs to the pea family, Fabaceae. People call it bighead clover or largehead clover. It comes from the western United States. It grows in regions with a temperate climate. Its range spans Washington and Oregon, plus southern Idaho. It also includes northeastern California and northern Nevada. It is not native to Britain or Ireland. In the wild, it grows on dry ground, often among rocks. It grows among sagebrush and beneath yellow pine.

This small plant reaches about 1 foot (0.3 metres) tall. It is a perennial, so it lives for several years. Each flower has both male and female organs. Insects carry pollen between the flowers. The supplied species account gives no dates for bloom. It does not state the flower colours, either. It also gives no details of the fruit or leaves. Its low height suits the garden beds that Plants For A Future lists.

For garden use, choose full sun and moist soil with good drainage. The account says it does not grow in shade. It accepts sand, loam, and clay, even in poor soil. It copes with soil from mildly acid to mildly alkaline. The stated best choice is soil close to neutral. Its wild sites are dry, but the garden advice calls for moist soil. Plants For A Future lists USDA zones 4–8 for this species.

Root bacteria form small lumps called nodules. They take nitrogen from the air. The plant uses some of this nitrogen to grow. Nearby plants can gain from part of that supply. Plants For A Future also lists it as a nutrient accumulator, a plant that stores nutrients. That source describes its use near apple trees. It claims this can benefit the fruit. It warns against planting near gooseberries or camellias. The clover can host a mite that harms those plants. Reports link it to fruit drop in gooseberries. They also link it to early buds in camellias.

You can cook the leaves and eat them as greens. Plants For A Future rates their food value as low. It reports no known hazards, but this does not mean all use is safe. The source lists no known uses in medicine or weed potential. To grow more plants, sow seed or divide plants in spring. Soak seed in warm water for 12 hours before sowing. Sow outdoors, or use pots in a cold frame. Move seedlings grown in pots to their own pots once large enough. Plant them out in late spring.