Calceolaria arachnoidea aka Cobweb Slipper Wort

Calceolaria arachnoidea belongs to the family Calceolariaceae. Its native range lies in south-central Chile. Kew lists it as a plant of temperate climates. It is not native to Britain or Ireland. Sources describe its growth form in two ways. Kew calls it a subshrub, while Plants For A Future calls it a perennial. These accounts describe a small plant that lives beyond one year. Its listed height reaches about 1.6 feet [0.5 metres]. The supplied sources give no mature spread.

Plants For A Future places flowering from August to October. Each flower has both male and female organs. The evidence gives no species-level account of flower colour or shape. Nor does it describe the fruit, bark, or leaves. The RHS page describes flowers and foliage for the genus as a whole. Those broad traits do not establish this species’ appearance. The available evidence therefore gives a clearer picture of its growing needs than its looks.

This plant can grow in full sun or partial shade. Plants For A Future lists sandy, loamy, and clay soils as suitable. It also accepts mildly acid, neutral, and mildly alkaline conditions. Moist soil suits it during active growth. Its water needs change with the season, however. The cultivation notes call for ample summer moisture and dry winter conditions. A site must therefore meet more than a general preference for moist ground. The same source lists USDA zones 8–11. It limits outdoor growing in Britain to the mildest areas. Its separate reference to UK zone 9 does not provide an RHS hardiness rating.

Cultivated beds are a listed garden setting for this species. Spring sowing under greenhouse cover offers one way to raise plants. Division in spring provides another route. Plants For A Future reports no known edible use. It records an astringent medicinal use, with a low use rating. It also lists the plant as a source of red dye. These records do not establish a safe home remedy or food use. The source reports no known hazards, but gives no specific pet-safety evidence. It marks the species as having no weed potential. The supplied material names no pests or diseases.