Willowherbs are annual or perennial forbs in the Epilobium genus of the evening-primrose family. Many of them are native to the Yuba-Sutter area.
Perennial
California Fuchsia
California fuchsia (also called hummingbird trumpet) is a two- to three-foot-tall by four-foot-wide, red-flowering, semi-deciduous willowherb that is native to Yuba County and typically grows at elevations below 10,000 feet. It is most often found on dry slopes and ridges in yellow pine forest. California dogface butterflies drink the nectar of its flowers.
You can read more about it at the Theodore Payne Wiki and the Las Pilitas Nursery website. You can see pictures of it at CalPhotos, Flickr, and Picasa. You can find out where to buy it at the California Native Plant Link Exchange.
Fringed Northern Willowherb
Fringed Northern willowherb is native to Yuba and Sutter Counties and typically grows at elevations below 13,500 feet. It is found in riparian forest. Botanist Willis Linn Jepson collected fringed northern willowherb in Marysville in 1934.1
You can see pictures of it at CalPhotos, Flickr, and Picasa.
Annuals
Denseflower Spike-Primrose
Denseflower spike-primrose is native to Yuba and Sutter Counties and typically grows at elevations below 8,500 feet. It is found in central oak woodland, valley grassland, and yellow pine forest. Botanist Willis Linn Jepson collected denseflower spike-primrose in Smartsville in 1934.2
You can see pictures of it at CalPhotos, Flickr, and Picasa.
Narrowleaf Spike-Primrose
Narrowleaf spike-primrose is native to Yuba and Sutter Counties and typically grows at elevations below 8,500 feet. It is found in central oak woodland, valley grassland, and yellow pine forest.
You can see pictures of it at CalPhotos, Flickr, and Picasa.
Tall Autumn Willowherb
Tall autumn willowherb (also called panicled autumn willowherb) is common in Beckwourth Riverfront Park Complex. It is native to Yuba and Sutter Counties and typically grows at elevations below 7,500 feet. It is most often found in disturbed, weedy habitats in central oak woodland, valley grassland, and yellow pine forest.
You can see pictures of it at CalPhotos, Flickr, and Picasa.
Little Chaparral Willowherb
Little chaparral willowherb is native to Yuba County and typically grows at elevations below 5,000 feet. It is most often found in disturbed, weedy habitats in central oak woodland and yellow pine forest. It tolerates serpentine.
You can see pictures of it at CalPhotos, Flickr, and Picasa.
Selfing Spike-Primrose
Selfing spike-primrose is native to Sutter County and typically grows at elevations below 1,000 feet. It is found in riparian forest.
You can see pictures of it at CalPhotos, Flickr, and Picasa.
Smooth Spike-Primrose
Smooth spike-primrose is native to Yuba and Sutter Counties and typically grows at elevations below 5,000 feet. It is found in riparian forest.
You can see pictures of it at CalPhotos, Flickr, and [http://picasaweb.google.com/lh/view?q=%22Epilobium+pygmaeum%22&psc=G&filter=1# Picasa.
Footnotes
1. Consortium of California Herbaria
2. Consortium of California Herbaria