Scientific name: Colletia paradoxa
Plant type: Perennial shrub
Environment: Full sun, well-drained soil
Bloom: Small, white, fragrant flowers growing close to the stem
Uses: Border plant or specimen plant
Anchor plant (Colletia paradoxa (Spreng.) Escal.) is a unique shrub from South America. It is native to northeastern Argentina, southern Brazil, and Uruguay. In this range Colletia paradoxa grows in temperate, dry regions. It is also able to fix nitrogen into a usable form, allowing it to grow in nutrient poor soils.
In Brazil, Colletia paradoxa is considered to be endangered due to habitat loss and the invasion of nonnative plant species. The anchor plant is also not very common in cultivation, though it was introduced into cultivation in California in 1909 by Dr. Francesco Franceschi. Dr. Franceschi was an Italian horticulturist focused on introducing new species to California that were suitable for its Mediterranean climate.
The structure of Colletia paradoxa is visually quite unique. The flattened triangles protruding from the stem are actually an extension of the stem, called cladodes or cladophylls. These cladodes act as leaves and are photosynthetic, with the chlorophyll necessary for the process giving them their green hue. The plant does produce small leaves on its new growth, but they are deciduous and fall off quickly. The cladodes are arranged opposite from each other on the stem, appearing like the anchor of a ship, giving the plant its common name. These “anchors” are tipped with small, sharp spines, protecting the species from grazing animals.
The anchor plant has small, white flowers that emerge close to the stem. The flowers are quite fragrant, with an aroma like almonds. The tiny flowers are typically pollinated by insects.
Though Colletia paradoxa can reach heights of over 10 feet, it is very slow growing and will take many years to reach that height. In the garden it would serve nicely as a border plant or an architectural specimen plant. C. paradoxa requires a sheltered location, protected from the elements, in full sun, with well-drained soil.
Featured Plant Contributors: Text, profile, and photos Victoria Stewart