The plant featured in today's photo, Manihot grahamii, sits about 4 metres from the entrance to our Physic Garden, in a large and Scotch thistle-filled concrete basin. As I walked toward the slope of the Alpine Garden in search of a different specimen one day early last week, I chanced upon each of this plant’s modest, half-concealed flowers in the act of hosting a single, silent honeybee. For reasons that require little elaboration, my trip to the Alpine Garden took somewhat longer than I had anticipated.
In the past two months, we have twice featured members of the quite large Euphorbiaceae (spurge family), the entries for which you can access here (17 June) and here (13 July). Manihot is a genus of about 98 species included in both the Subfamily Crotonoideae and, along with the spurge nettle (Cnidoscolus stimulosus), the Tribe Manihoteae. The genus is perhaps best known for one of its species, Manihot esculenta or cassava, which is commonly cultivated and treated as a staple crop throughout the tropics, particularly in the warm South American regions to which it is native.
Manihot grahamii—variously known as Graham's cassava and hardy tapioca—is a self-pollinating, cold hardy herbaceous shrub or tree that quickly grows to a height of between 3 and 5 metres when exposed to full sun or partial shade. It is native to the eastern half of South America, from Brazil through Uruguay and Paraguay to Argentina. In today’s photo, the plant's small, dangling flower, which is equipped with 5 purple-tipped petals, is set against a cluster of powerful dehiscent capsules that can project seeds no inconsiderable distance away from the parent plant. While the singularity of my encounter remains somewhat intact, in the interim I've learned that honeybees are known to adore these flowers, and that the concentration I witnessed was by no means unprecedented.