The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.
Most physical descriptions on Troutnut are direct or slightly edited quotes from the original scientific sources describing or updating the species, although there may be errors in copying them to this website. Such descriptions aren't always definitive, because species often turn out to be more variable than the original describers observed. In some cases, only a single specimen was described! However, they are useful starting points.
This is another brownish, pale-legged species with diffuse pale basal rings on the middle abdominal segments. Head and thorax brown above, with the sides and the terminal abdominal segments paler brown. Legs pale brown, whitish beyond the knees. Wings sub-hyaline with pale brown veins. Cross veins nearly obsolete in most of the costal space; single and straight and spaced well apart in the stigmatic region. The brownish rings upon segments 2-7 of the abdomen are very diffuse and ill defined and only slightly darker on segments 2 and 7 than on the intervening segments. The black of the spiracle is extended rearward in an R-shaped line covering the postero-lateral angle. The basal segment of the forceps is tapered to three-fourths its length. There is a wide V-shaped notch between the two penes. The sperm duct ends in a long straight, tubular process on the outer sides of which stands a long spirally twisted spine (see fig. 133).
This species differs from P. pallipes (now a synonym of Neoleptophlebia memorialis) in that the above mentioned spine lies in the same plane as the tubular process, not curving upwards as in that species.