Triteleia laxa aka Ithuriel's Spear

Triteleia laxa is a perennial that grows from underground corms. Its common names include grass nut and Ithuriel's spear. It belongs to the asparagus family, Asparagaceae. Kew lists its native range as California. Plants For A Future also includes southwestern Oregon. Wild plants grow in woods, foothill grasslands, and heavy soils. Some sites have clay soil. These habitats range from sea level to about 4,920 feet [1,500 metres].

Garden plants reach about 1.25–1.67 feet [0.38–0.51 metres] tall. Sources differ more on their width. RHS gives a spread of about 0.33 feet [0.1 metres]. NC State gives 0.75–1.5 feet [0.23–0.46 metres]. Long, narrow green leaves rise from the base. The plant sheds its leaves rather than keeping them year-round. Bare stems hold loose umbels of funnel-shaped blooms. Flowers range from mid-blue to deep blue or purple. NC State also records white flowers with violet stripes. Blooms appear in late spring or early summer, including June.

Grow this plant in full sun for the conditions both sources support. NC State also allows part shade. Choose fertile soil that drains well. RHS favours light, sandy soil or loam. NC State lists a wider range, including clay. Both sources allow acid, neutral, or alkaline soil. Give steady moisture during spring and early summer growth. Keep the soil dry after flowering until the next spring. Established plants tolerate drought. Plant corms in autumn, and guard against frost and winter wet.

RHS rates this species H3 for mild UK sites. NC State lists USDA zones 5–9, with limits at the cold end. Its guidance calls for shelter and mulch in zone 5. Containers offer another way to provide dry winter storage. Use the plant in borders, informal beds, or naturalized areas. The flowers last well and suit cutting. Native bees feed at the blooms. Plants need no pruning, and reported pest and disease problems are few. Divide dormant corms or raise plants from seed. Seed-grown plants may take two to three years to flower.

Plants For A Future records the underground storage organ as edible. It describes a sweet, starchy food eaten raw or cooked. The source reports no known hazards, but gives no pet-safety assessment. It lists no known medicinal uses or other practical uses. Its weed assessment does not flag this species as weedy.