Petasites ×vitifolius Greene
[= Petasites frigidus var. ×vitifolius]

Washington: King County: Muddy pools and gravelly shores of Williams Creek. c. 70 m from confluence with Swauk Creek. 0.1 km E of junction with Liberty Road and Route 97. Elev. 750 meters
47.2433° N, 120.695° W; T20N R17E S10
Coordinate Source: Field measured. Invalid coordinates (located outside county bounds).
Full sun. Associated taxa: Scirpus microcarpus, Heracleum, Salix, Spiraea, Rosa. (P. Frigidus var. palmatus x P. sagittatus) Flower white or purple-tipped; Disk corolla lobes 1.4-1.8 mm long; Disk syles branched 0.4-0.5 mm; Style + branches 3.0 mm; Ray florets/hd 14-16; Rays 2.8-3.0 mm long; 28 female fl/head; Male flrs withered.

Peter F. Zika 19411, Apr 22, 2004
WS, Accession: 371711