Monday, May 11, 2015

Rugel's Hoarypea - Tephrosia rugelii

Rugel's hoarypea (Tephrosia rugelii) is endemic to Florida, but found in most counties in the peninsula as well as being reported from Jefferson County.  It is one of eight species found in Florida; a genus that can sometimes be confusing. Hoarypeas are legumes and they share the many characteristics of the family - compound leaves and flower shape, to name two.
Rugel's hoarypea is similar to Florida hoarypea (T. florida) and can be told apart mostly by the length of the petiole - the part of the leaf that attaches it to the main stem.  Rugel's hoarypea has much shorter petioles than Florida hoarypea.  Both species are common in upland well-drained sites and bloom from late spring into fall.  The specimens above were photographed in Kissimmee Prairie Preserve State Park, not in sandhill, but where the water table often rises to the surface during wet summers.
This is a perennial that dies back to the ground in winter.  Its stems are herbaceous and they are upright, though they grow outward more than upward and extend for several feet from the root in many directions.  The compound leaves are comprised of many elliptical leaflets, ending in a sharp point.
The blooms are interesting.  The deep rosy buds open by mid-morning, producing bright white flowers. By late afternoon, these blooms turn rosy once more before closing.  This makes it easy to identify this plant as two separate species, but of course, it is not.
Tephrosias are of great interest to pollinators such as bumblebees and serve as larval food for several butterfly species - including several species of skippers.  None, however, have ever been propagated to my knowledge by any of the native plant nurseries associated with FANN - the Florida Association of Native Nurseries.  Tephrosias, like Rugel's hoarypea would make a useful ground cover within a naturalistic mixed wildflower garden.  Perhaps someday at least one of them will be offered for that purpose.

Sunday, May 3, 2015

Whitetop Aster - Oclemena reticulata

Whitetop aster, also known as pinebarren aster, (Oclemena reticulata) is one of many asters formerly included in the genus Aster, and now distinguished within a new and separate genus.  This species is the only one included in Oclemena, and it has characteristics that separate it from the many asters now included in Symphyotrichum. This species is found nearly statewide, except extreme south Florida and in states immediately north of us - Alabama, Georgia and South Carolina.  It is common to open prairies and moist pine flatwoods.
Whitetop aster is a perennial that dies back to the ground in winter and quickly reemerges in the early spring.  Its many stalks reach a mature height of about 3 feet by April.  Unlike other asters, it blooms in April to early May, sets seed shortly after and then largely stays dormant the rest of the growing season.  It leaves are oval, lime green in color, with a few teeth along the margins and with deeply incised veins.  These are on thin, but stiff stems.  Whitetop aster spreads by underground rhizomes in good growing conditions and quickly forms extensive colonies.
The flowers are typical of many "asters"; the ray petals are thin and white, surrounding a central core of yellow disk flowers.  The loose panicle of blooms stands well above the foliage and attracts a diversity of pollinators.  Unlike the vast majority of other "asters", these blooms are available early in the season and therefore can be a critically/valuable resource to bees, butterflies and other pollinating insects.
Whitetop aster is only rarely available from commercial sources, despite its utility and understated beauty.  In the home landscape it requires sun and relatively moist soil - especially during the spring and summer.  It will slowly decline if kept too dry.  In the right conditions, it can become a problem because of its tendency to sucker and spread, but this can be controlled through occasional thinning.  Do not use it in small mixed wildflower beds, but in more expansive areas it provides color at a time when few other wildflowers are blooming and it becomes a magnet for bees and butterflies. I have recently collected seed of this species and we hope to make it available by fall 2015.