Tuesday, 23 December 2008

Begonia angularis

Illustration from Curtis's Botanical Magazine, 1902

I'm pleased to have finally tracked down this one. Identified the old fashioned way from the b+w photos in Alfred Graf's Exotica. (mine is the 8th edition 1976 - over 1800 pages in a single volume, and before the internet your only hope of identifying an unknown exotic plant!) For many years I have grown this as B. ulmifolia since it is grown under this name in some Lisbon collections, but apart from the asymmetrical leaf base (which nearly all begonias have) this leaf owes nothing to the elm. The true ulmifolia has puckered or bullate leaves and looks just like the leaf of an Elm!

This was possibly the "Begonia arborescens" of Walter Oates, Monserrate 1929 (See posting) It grows easily to two or more metres high. Tough and robust it has survived in a number of old Sintra gardens. Notably at Quinta do Relógio and in a villa garden on the Rua Dom João de Castro, just below Quinta Nova. Flowers all year round. Angular-stems (a key identifying characteristic) and large leathery smooth leaves. Local gardeners call it the "Lingua da Vaca" or Cow's Tongue.
Native to steep, shady, moist areas in the central region of the Atlantic Coastal forest of Brazil at an altitude of 600-1500 m. This forest is home to almost 200 Begonia species. Commonly cultivated Begonia species from this forest include B. coccinea, B. convolvulacea, B. cucullata, B. herbacea, B. luxurians, and B. venosa. 90% of Brazil's Atlantic Coastal Forest has now been destroyed, but there are now large areas protected within the National Park System.
See Begonias By Mark C. Tebbitt, Brooklyn Botanic Garden p. 83-4 Timber Press
Originally collected from San Gabriel in the Serra d'Estrella, near Rio. Distributed to gardens in 1845. Grown for many years at Kew in the Temperate House, where it grew to a height of eight feet.
Begonia angularis Raddi
Section Pritzelia - cane-like group of shrubby Begonias
Synonyms: Pritzelia angularis; B. compta Bull; B. crenulata Schott; B. zebrina Hort. Angl.; B. hastata Vell. Fl. Flum.; Pritzelia zebrina Klotzsch.

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