[Stickseeds and Tickseeds: The Genus Hackelia East of the Cascade Mountains of Oregon and Washington]

What might be Okanogan stickseed as seen about one-half mile south of the Little Spokane River on Missoula Flood sandbars.........May 23, 2010.

Additional close-up views of what might be Okanogan stickseed as seen about one-half mile south of the Little Spokane River on Missoula Flood sandbars..........May 23, 2010. Notice the small intramarginal prickles on the faces of the nutlets. Also note some of the flowers are pinkish.

What may be Okanogan stickweed as photographed on a Missoula Flood sand bar about one-half mile uphill from the Little Spokane River..........June 21, 2009.

Two close-ups of the flowers of what appears to be Okanogan stickseed as photographed on a Missoula Flood sand bar about one-half mile uphill from the Little Spokane River..........June 21, 2009. The flowers range from mostly white with a slight blue tinge to a light powder blue. There are some minute, papillate hairs on the yellow fornices at the center of the disk.

Three close-up views of the prickly nutlets of Okanogan stickseed. Note that the marginal prickles are united at the base for about one-half their length, forming a cup-like border. There are a few small intramarginal prickles in the central area of each nutlets main disk. Photographed on a Missoula Flood sand bar about one-half mile uphill from the Little Spokane River........June 21, 2009.

The basal leaves and lower stem of what appears to be Okanogan stickseed as photographed on a Missoula Flood sand bar about one-half mile uphill from the Little Spokane River.........June 21, 2009. Some of the hairs on the lower stem spread downward.