Today’s photo and article come from Tom Wheeler. Tom is a horticulturist working on the Garry Oak Meadow and Woodland project at UBCBG.
Mentzelia was named by Linnaeus in honour of Christian Mentzel (1622-1701), a German physician, botanist and lexicographer. The epithet laevicaulis (laevi = smooth + caulis = stalk) refers to the comparatively smooth stems of this species in comparison to other Mentzelia species.
To see Mentzelia laevicaulis, or blazing star, on gravelly cuts and slopes in BC’s southern dry interior region is to revel an exquisitely different representative of the region’s flora. This biennial or short-lived perennial is native to much of western North America from near sea level in the north to 2440 m (8000 ft.) in the southern parts of its range.
The fragrant, lemon yellow flowers can be up to 16 cm across, opening at mid-morning and remaining open past dusk and throughout the night. Carpenter bees and hawk moths are the blazing star’s vespertine (evening) and nocturnal pollinators, and daytime opening enables other pollinators, including European honeybees, to visit, as well. When its flowers are open, their presence dominates the plant, but the short, barbed, hairy upper stems and branches give this species its other common name, stick-leaf, for its leaves and stems easily stick to clothing.
Mentzelia includes annuals, perennials, sub-shrubs and shrubs. The centre of diversity is southwestern North America, but the range of the genus extends to Argentina and Chile. California is home to more than half of the 50 species. While the family Loasaceae is well known for nasty plants with stinging hairs (e.g., Cevallia, the stinging serpent and Petalonyx, the sandpaper plant), the blazing stars are generally easily handled.