3. Olympic rockmat (Henderson's rock spirea), Petrophytum hendersonii

Blooms July to August

Found in bedrock cracks and talus slopes although I have not yet found any in talus.

 

            The Olympic rockmat appears to be closely related to the Tufted rockmat (P. caespitosum) but there is no overlap between the ranges of these cousins.  The Olympic is, of course, found only in the Olympic mountains while the Tufted is found in the Rocky Mountains and Great Plains of eastern Oregon, Idaho, Montana, and points to the south and east.  Additionally, the leaves of the Olympic rockmat has three veins underneath while the Tufted has only one vein, and the Olympic has 35 to 40 stamens in each flower group compared to the Tufted having about 20 stamens. 

            This plant is also only a few inches tall.  The woody stems are densely covered with paddle-shaped hairy (top and bottom) leaves.  There is frequently a gap of approximately 1 inch between the top of the leaves and the bottom of the flowers.  The tiny flowers are in a conical cluster about 1 inch long looking not unlike a off-white cotton ball.  Multiple clusters of flowers can be found above a mat of leaves.  I am unclear if this is considered a single plant or multiple individuals.