A Reassessment of the Rhododendron verticittatum Low ex Lindl. Complex with a New Species, R. atrichum Argent and Two Subspecies, subsp. atrichum and subsp. dendrolepis (Argent) Argent

摘要

Rododendron verticillatum Low ex Lindl. was treated by Sleumer (1966) as having two forms: forma verticillatum and forma velutinum (Beec.) Sleumer. Forma velutinum was reduced to synonymy in Argent (2006) after an examination of the type specimen of forma verticillatum in the Cambridge herbarium which showed that this had hairs on the petioles and leaves, the important distinguishing characters for forma velutinum. There is an uncharacteristic vagueness about the distinctions between the two formae in Sleumer's Flora Malesiana account (Sleumer 1966). The flowering in cultivation of a Rhododendron collected by the Jermy, Mulu (Sarawak) expedition prompted a re-examination of herbarium specimens in the Kew and Edinburgh herbaria. This showed that there were both hairy-leaved and just scaly-leaved plants under Rhododendron verticillatum, further there were collections with rounded to lobed scales, stellate scales and distincdy dendroid scales which appear to form three distinct entities.