E-Flora BC: Electronic Atlas of the Flora of British Columbia

Species description:
Photobiont a lime-green to grass-green alga; upper surface generally greenish, especially when wet (Note: check sheltered lobes); wart-like cephalodia sometimes present over upper or lower surface AND
Cephalodia absent over upper surface; upper surface smooth AND
Thallus attached to substrate at single point along margin; veins darkening, generally highly contrastive with pale interspaces; apothecia present, situated near lobe margins, never sunken

Comments:
The cephalodia of P. venosa may become detached and develop into the tiny, Leptogium-like lobules often found growing at the base of this species.

Contents:
Green phototype: phlebic acid A and B, tenuiorin, zeorin and one unidentified substance (Kurokawa et al.1966); blue-green phototype: no lichen substances reported (Tønsberg and Holtan-Hartwig 1983).