The handsome , fissured , gray-brown bark .
PURPLE HAZE “ It makes for a wonderful summer show offset against the white flowers over a long period ,” says UW Botanic Gardens Interim Director and Curator of Living Collections Ray Larson .
The Arboretum ’ s specimens are tagged as Stewartia ovata var . grandiflora , and the purple coloring is found in some wild populations . However , American botanists no longer recognize the designation of the purple-filament plants as a distinct and stable variety .
“ They are now considered by more recent taxonomic work to be part of the natural variation within Stewartia ovata ,” says Ray , “ or perhaps the product of some hybridization with Stewartia malacodendron , whose range it overlaps with .”
Stewartia malacodendron , the silky camellia , is the only other stewartia native to North America ( and the only other non-Asian stewartia ). It , too , is a beautiful plant that ’ s similar in form , leaf and flower to S . ovata . And , wouldn ’ t you know , the stamens have purple filaments ! Bloom time , however , is generally earlier — in late spring — and the anthers are a bluish color . There are also more subtle morphological differences , such as in the number of winter bud scales . And in general , the plants don ’ t grow in the same environment : Silky camellia is associated more with the coastal plain of the Southeast , while S . ovata is found in upland areas .
Whatever the origins of the mountain stewartia with the purple filaments , there ’ s no doubting its desirability as a garden plant . Besides the fabulous flowers , S . ovata also has attractive orange-to-scarlet fall color , and its fissured , gray-brown bark is not without its charm .
6 v Washington Park Arboretum Bulletin
ARBORETUM SPECIMENS The four specimens in the Arboretum date back to 1941 .
“ Ours are all from the same source ,” says Ray , “ purchased by the ‘ Amateur Gardeners ’ club , which sponsored work in the Camellia section in the Arboretum . We received 20 of them as 18-inch tall plants from the club president , Mary Williams , who would later be memorialized with a planting area and stone bench installed in the Camellia Collection , close to the stairs leading down from Arboretum Drive into the Rhododendron Glen . We have records of a planting in spring 1948 but are not sure how many were originally were planted out .”
“ Interestingly ,” continues Ray , “ the specimen 850-41-D , which is on the east side of Arboretum Drive , opposite the Williams memorial bench , was noted as being the National Champion of the species when it was measured in 2004 at 26 feet tall .”
This specimen is tree-like in form , with a single , eight-inch-wide trunk . In recent years , it has become somewhat shaded out by a much larger S . monadelpha growing next to it . Two of the other four specimens of mountain stewartia can also be found along Arboretum Drive , on the west side of the road , just a little south of the Williams bench . These plants are shorter and shrubbier and right on the border of the planting bed , so it ’ s easy for visitors to get up close and personal with the flowers . The fourth specimen , another tree-like stewartia , is deep in the heart of the main Camellia grove on a steep slope not far west of the main trail .
Mountain stewartias thrive in conditions similar to those preferred by camellias : moist , well-drained , acidic soils and partial shade . Ray plans to add more to the Arboretum collection in the coming years , though he says they can be hard to find in the nursery trade . That ’ s a shame because this southeastern beauty clearly does well in our region and would make a stunning addition to any shrub border or as a specimen planting in the garden . m
Niall Dunne is the editor of the “ Bulletin ” and the communications manager at the Arboretum Foundation .