Featured rhododendron:  R. hyperythrum.

Rhododendron hyperythrum is a species which is native to a small area at lower elevation (3000-4000 ft) in the mountains of northern Taiwan.   It is of particular interest to us in the Southeast because of its heat and drought tolerance, probably related to a vigorous root system, resistance to Phytophthora root rot, and relative cold tolerance.   It gets its name from the presence of minute red-brown dots on the leaf undersurfaces.   It has easily recognized characteristic recurved leaves, although it is said that in the wild habitat, the leaves are flat.   Flowers  have pinkish buds, opening to white, with pink, red or purple speckles, with some pure white forms, and rare pink flowered forms.   Some plants feature bronze new leaf growth.   Flowering time is early in the season (early April in upstate South Carolina), so that flowers are sometimes affected by late frosts.   It is considered to have a maximum height of 6 feet, but we have some older plants which are over 15 feet.   The slide show illustrates flower variation between our different seedling plants of R. hyperythrum (most of which were raised from a single "bonus" pack of seed from Esther Berry of the ARS Seed Exchange in the early 1970's).
Jackson McCarter,M.D.  

R. hyperythrum as a parent for heat tolerance and Phytopthera resistance:

Developing Heat Tolerant Rhododendron Hybrids with Disease and Insect Resistance using R. hyperythrum, Stan Southerland
http://scholar.lib.vt.edu/ejournals/JARS/v53n3/v53n3-means.htm
http://www.elkridgegarden.com/research1.html
http://ipps-srna.org/WordPress/wp-content/uploads/2013/12/3B-Krebs-Steven.pdf
http://atlanticrhodo.org/wp-content/uploads/2015/02/Moving-Forward-with-Leach-Hybrids-Halifax-2014-compressed.pdf
https://www.ces.ncsu.edu/fletcher/mcilab/publications/ranney-etal-1995a.pdf
http://www.apsnet.org/meetings/Documents/2012_Meeting_Abstracts/aps12abP248.htm