Caldcluvia is a monotypic genus of flowering plants in the family Cunoniaceae, order Oxalidales. It contains a single species, Caldcluvia paniculata, commonly known as tiaca, an evergreen tree native to the temperate rainforests of Chile.
Tiaca grows up to 20 m (65 ft) tall with trunk diameters reaching 60 cm (24 in). The bark is grayish brown, and the leaves are oppositely arranged, oblong to lanceolate in shape, 7–15 cm long and 2–4 cm wide, with toothed margins. The upper leaf surface is glossy green; the underside is whitish and somewhat hairy. White flowers are borne in axillary panicles; each flower is hermaphrodite, with 4–5 hairy sepals, 4–5 petals, 8–10 stamens, and 2 styles. The fruit is a pointed (acuminate) hairy capsule crowned by persistent styles, containing dark brown seeds approximately 1 mm long.
Although the genus once encompassed a broader set of species, molecular and morphological revisions have transferred most of these to related genera — principally Ackama, Opocunonia, and Spiraeopsis — leaving Caldcluvia as a monotypic genus. Plants of the World Online recognized only Caldcluvia paniculata as of April 2021.
Etymology
The genus name Caldcluvia honours Alexander Caldcleugh (sometimes spelled Caldcleugh), a Scottish botanist who travelled through South America between 1819 and 1825, collecting specimens for the Royal Botanic Gardens, Kew. The species epithet paniculata is Latin for "with panicles," referring to the branched flower clusters.
Distribution
Caldcluvia paniculata is native to Chile, occurring along a narrow latitudinal range from the Ñuble Region south to Aisén, roughly 36–45°S. It grows in wet, temperate forest and is classified in USDA Hardiness Zone 9. The tree has also been planted in Northern Ireland as an introduced ornamental.
Cultivation
The leaves of Caldcluvia paniculata are used as a herbal tea in Chile, traditionally taken for colds and stomach disorders. Propagation from seed is possible but slow and unreliable, with germination success rates below 30%. The tree tolerates up to 40% shade and may benefit from partial shade in some locations, though it requires a consistently wet climate.
Taxonomy Notes
Caldcluvia was historically treated as a broader genus within Cunoniaceae. Subsequent revisions relocated most of its former members to Ackama, Opocunonia, and Spiraeopsis, reducing it to a monotypic genus with Caldcluvia paniculata as its sole accepted species. GBIF places the genus in order Oxalidales, family Cunoniaceae.
