(American pasqueflower)
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Photo of Pulsatilla patens by Jacob Frank
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Pasqueflower is a beautiful early spring flower in the buttercup family (Ranunculaceae), with large, lavender-blue blossoms and soft-hairy stems. Pasqueflower occurs scattered in open woods and subalpine sites in Denali. Plants grow from a branching caudex, covered in old leaf bases. Plants are short early in the season (10-15 cm), elongating in flower to 25-35 cm. The basal leaves are three-parted, deeply cleft into narrow,
linear segments. The whole plant is densely white-wooly in bud, both the
bracts beneath the flowers and the stems. Flowers are pale blue to deep lavender. The
tepals are
ovate and pointed, with long white hairs on the outer side, appressed to the surface. Each flower has 150-200 yellow
stamens, surrounding many white-styled
pistils. The fruiting head is composed of many densely hairy
achenes, looking similar to a dandelion or cottongrass seed head. There is no other spring-flowering plant with large purple blossoms and silky-haired stems.
Pasqueflower is one of the first wildflowers to be seen in the spring. The flower buds emerge shortly after snowmelt, before the basal leaves grow.
Stigmas turn from white to pink or pinkish brown after pollination. When the flower is in bud, the stalk elongates below the
bract. Once the head starts to set fruit, the stem grows above the
bract (
Ordway 1984).
Pasqueflower is
monoecious with bisexual flowers. The species is bee-pollinated, nectar-producing, and also self-compatible (
Ordway 1984). The species is protogynous (
stigmas develop before pollen is released), but there is a considerable overlap between the period of
stigma receptivity and
anther dehiscence. Pasqueflower does not automatically self-fertilize, but has fairly high fruit set with experimental self-fertilization. The highest seed-set and seed germination, however, occurs in outcrossed plants (
Lindell 1998). Seeds have a long plume, allowing them to be wind dispersed.
Pulsatilla patens occurs in western North America, from Alaska eastward to western Northwest Territory, south through Alberta and Saskatchewan to northern New Mexico and east to Wisconsin and Illinois. In Alaska, the species range is primarily in the central and eastern interior and the north side of the Alaska Range. A few localities are known from the North Slope, the Seward Peninsula and near Copper Center. In Denali, this species occurs in the northeastern quadrant of the Park, including the area around Park Headquarters.
Details are shown in the Plots & Charts found at right, depicting recent Denali data.
The eleven specimens from Denali occurs at an altitudinal range of 459 to 1021 m, with an average elevation of 716 m. These plants also came from moderately steep slopes; the average inclination is 18 degrees. The majority of specimens (7 out of 9) were found on south-facing slopes.
Details are shown in the Plots & Charts found at right. For more on how to interpret these figures, visit Understanding Data Presented.
Dry sites.
