Phacelia sericea, commonly known as Silky Scorpionweed or Silky Phacelia, is a species of flowering plant in the family Boraginaceae, the borage and forget-me-not family. It’s a species that is endemic to North America (meaning that it’s found nowhere else in the world). It can be found in Alberta and BC and through the western U.S. as far south as the mountains of Arizona. As well, there is a population in Alaska and the neighbouring Yukon that is “disjunct” – disconnected from the rest of the plant’s range.
Silky Scorpionweed is herbaceous, dying to the ground in winter, sprouting again in spring. It’s also perennial; individual plants usually survive for more than one year, blooming and producing seed each year. The plant has alternate, deeply lobed leaves that are covered in fine silky hairs, giving it a distinctive appearance.
The flowers of Scorpionweed are pale blue to lavender or purple and funnel-shaped with the tips of the flower tubes divided into 5 equal petals. The thing that folks mostly notice, though, is the cool spikes sticking out of the flowers! These are stamens (the pollen-producing flower structures) which are 2 or 3 times as long as the flower itself (click on the photo at right to see how cool they are)!
Silky Scorpionweed is a curious name! Scorpionweed is the common name for the genus, Phacelia. It comes from the observation that some Phacelia species have flowers in long, coiled clusters along the stem, somewhat resembling a scorpion’s tail. Phacelia sericea actually has flowers in short clusters but, nonetheless, it shares the genus common name of scorpionweed, plus it has silky-haired leaves, hence “Silky Scorpionweed”.
The height and form of Silky Scorpionweed vary quite a bit with elevation and conditions. On high alpine ridges, where exposure to extreme conditions keeps many plants compact, it may only get to about 15 cm (6 inches) and flower heads are often dense and short, as pictured at right. Lower down in less exposed conditions, it can reach to about 40 cm (16 inches), and flower heads are usually much longer and more open.
Bloom time is from the end of May through August, and sometimes even into September. The flowers are attractive to pollinators, especially bees and butterflies.
Where to find them
Silky Scorpionweed is a common plant that can be found in open, rocky areas and in grasslands through the foothills and up into the subalpine and alpine throughout K-Country and also through the rest of the Alberta mountains trend to the south and through Jasper National Park to the north. It likes open, dry habitats and is especially fond of bare, rocky slopes and even disturbed areas such as roadcut slopes. Some good places to see it are where it covers the upper slopes of the Mt. Lipsett trail, in rocky dry soils near Spray Lake, and in the steep, rocky roadcut slopes along Highway 68 in eastern Kananaskis.
Silky Scorpionweed is sometimes cultivated as an ornamental plant for its attractive foliage and spectacular flower clusters, although it can be short-lived unless provided with the very good drainage that it favours in nature. It can be used in wildflower gardens, xeriscaping projects, and native plant landscapes.
See more of the pretty flowers on K-Country here.