Collinsia tinctoria aka Sticky Chinese Houses

Collinsia tinctoria is rated moderate to grow within its California native range, where it self-sows as an annual in woodland and chaparral conditions. It is rarely cultivated outside its narrow endemic range, and only a single California native nursery is recorded as supplying it.

This is a small annual herb that produces a single sturdy, erect stem reaching about 60 centimeters (8 to 24 inches) tall in a single growing season. Like other annuals, it completes its life cycle in one year, then dies back after setting seed.

Collinsia tinctoria is endemic to California, where it grows in the woodlands and forests of the central and northern mountain ranges, including the Cascade Range, Klamath Mountains, Sierra Nevada, and California Coast Ranges. It is not known to occur natively outside California.

In the wild it grows on rocky sites in chaparral, foothill woodland, red fir forest, and yellow pine forest, indicating a strong preference for sharply drained, often coarse-textured forest and scrub soils. It is generally a non-wetland species and rarely occurs in saturated ground.

Flowers are arranged in widely spaced, dense whorls along the upper stem and have five elongated, rounded-tipped sepals and a corolla that angles sharply downward from the calyx. Color is unusually variable — ranging from white and cream to yellow, pink, red, and deep lavender — and is often mottled, speckled, or tinted in the throat. The inflorescence and flower parts are glandular and hairy, giving the plant its "sticky" common name.

Collinsia tinctoria belongs to a genus of about 20 species of North American annuals commonly called blue-eyed Marys or Chinese houses. Two heterotypic synonyms — Collinsia barbata Bosse and Collinsia septemnervia Kellogg — were once described as separate species but are now treated as the same plant.

In its native range, Collinsia tinctoria thrives in deep shade to partial shade on rocky sites in chaparral, foothill woodland, red fir forest, or yellow pine forest, with very low water once established. As an annual, it relies on self-sown seed each year and is best treated as a wild or naturalistic woodland-garden plant rather than a manicured ornamental.

The flowers attract bees and butterflies, and the plant is a confirmed larval host for Edith's checkerspot butterfly, whose caterpillars feed on Collinsia and related Plantaginaceae. This points to insect pollination as the primary mechanism in the wild.

Sticky Chinese Houses should be watered regularly, allowing the soil to dry out between waterings.

To ensure optimal growth, the Sticky Chinese Houses prefers bright indirect light for 6-8 hours each day. Insufficient light can result in slow growth and leaf drop, so it's important to find a well-lit location for this plant. Place it near a window, within a distance of 1 meter (3 feet), to enhance its potential for thriving.

Ploi lacks confirmed information on the toxicity of this plant. If you, a relative, or your pet accidentally consume plant material with unknown toxicity, it's best to consult a medical expert.