The 2011 ASHS Annual Conference

One-hundred mile Rhododendron natural community is one of the natural wonders, which nourishes more than 40 taxa of Rhododendron. After several years of exploration, the complexity of mixed forests and difficulty for taxon delineation brought our attention. Although eight new species had been documented and more than 10 unidentified taxa had been listed, many natural hybrids could be directly keyed out from morphological features. Rh. delavayi is one of the dominant species in the community and it could be crossed with Rh. agastum, Rh. irroratum, as well as Rh. decorum. From wild selection, a total of 16 clones had been collected and evaluated for their stability of morphological characteristics and ornamental potentials. Seeds had been collected from questionable taxa and germinated. More than 40,000 seedlings had been transplanted for further evaluation and selection. Artificial hybridization has been initiated with goal to extend bloom seasons and duration, increase diversity of flower size and color, and select commercial feasible plants. From 33 identified taxa, the diversity of flower colors is from white (Rh. decorum, Rh. petrocharis), yellow (Rh. ambigum, Rh. molle), pink (Rh. agastum, Rh. denudatum), purple (Rh. brevinerve), to deep red (Rh. delavayi, Rh. rufohirtum). Flower size ranges from 1 to 12 cm in diameter and corolla shape from tube to funnel to bell. Rh. mucronatum has fragrance during its bloom. To properly utilize these source plants, we look forward to breeding better Rhododendron for our demanded nursery market.