(Macoun's woodroot)
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Photo of Podistera macounii by Adolph Murie
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Podistera macounii is a small alpine plant with a dark red umbel
bracts and white flowers. Plants grow 5-20 cm tall from a long taproot. The caudex is sheathed with older leaves. The leaves are all basal, shiny and dark green, long-
petioled,
oblong to rounded in outline, and pinnately divided. The leaflets are deeply
lobed, 3-12 mm long. Each plant has usually one, sometimes a few, flowering stalks. The stems are stout, green or purplish, leafless, bearing one compact, terminal umbel. Umbels have 5-20 rays, and several
bracts beneath. The many small flowers are
perfect, with minute white or purple petals. Each flower produces an
achene with many seeds, cylindric-
ovate with thick ribs, red-green in color.
Podistera macounii is hard to confuse with other species once recognized; there are no other species of rocky alpine tundra with
pinnate leaves and small purple or white flowers in small, compact umbels. The leaves of
P. macounii are similar to those of
Thalictrum alpinum, which has very different flowers, borne along an elongated
raceme.
This species flowers in the spring, shortly after snow melt, and is perennial.
Podistera macounii is
monoecious. No studies on pollination of
P. macounii have been carried out. Fruits release numerous small seeds, dispersed by wind and gravity.
Podistera macounii is an amphi-Beringian endemic species. The center of this species range is Alaska, with scattered localities occurring in neighboring Yukon, Northwest Territory and Chukotka, Russia. In Alaska, this species occurs in the alpine of the interior to west coast regions. The species apparently does not occur in the Brooks Range, but spans the alpine areas from the Yukon-Tanana Uplands and Ogilvie Mountains, to the north side of the Alaska Range, the Seward Peninsula and southwestern Alaska, reaching Aniakchak Bay on the Alaska Peninsula. In Denali, the species is relatively common in the alpine in the northern half of the Park, from slopes near Swift Fork of the Kuskokwim River to the Teklanika Mountains. A few specimens also occur south of the Alaska Range in the upper Chulitna River drainage.
Details are shown in the Plots & Charts found at right, depicting recent Denali data.
Though this species is found in a wide range of elevations (652-1676), it is a high elevation species. Almost all specimens in Denali are from above 900 m, and its peak frequency occurs above 1100 m. This species appears to be slightly more common on north-facing slopes, though specimens from southern aspects occur on a wider range of elevations. It is found on all inclines, especially 20-28 degrees.
Details are shown in the Plots & Charts found at right. For more on how to interpret these figures, visit Understanding Data Presented.
Well-drained moist to dry sites in the mountains.
