RARE PLANTS OF RIVERSIDE COUNTY

 

San Jacinto Valley Crownscale

Atriplex coronata var. notatior

 

By Fred Roberts, Rare Plants Co-Coordiinator

 

Federal: Endangered (November 1998)

CNPS List 1B.

R-E-D Code: 3-3-3

 

The San Jacinto Valley crownscale is an erect, gray-scruffy annual that grows from 10 to 30 cm tall.  It is a member of the Goosefoot family (Chenopodiaceae).  It has wedge-shaped tapered leaves with smooth or wavy margins.  The flowers, blooming from March to October, are grey-green and obscure. The fruits are the most distinguishing feature. These consist of some what rounded bracts with a dense covering of tubercles.

 

This saltbush is endemic to western Riverside County where it occurs on alkali soils (mostly of the Willows Soils series)  in seasonally flooded alkali vernal plain vegetation.  This association is made up of alkali playa, alkali scrub, alkali annual grassland, alkali vernal pools.  Similar habitat was once common in the Great Valley of Central California and not surprisingly, a similar array of species is found in both areas. Historically over 32,000 acres of this low, often dry and scruffy appearing habitat was found mostly immediately west of Hemet, about Mystic Lake, along the San Jacinto River flood plain, and along Nicols Road northwest of Lake Elsinore.  Less than a third of this habitat remains today and a good deal of this is disturbed by dry land farming, discing, and the addition of soil amendments.  For this reason, the U.S. Fish and Wildlife proposed this species as endangered in 1994.

 

About 10 poorly defined populations of crownscale have been identified.  The most extensive population complex  is found from the vicinity of Mystic Lake to the Kaiban Hills along the San Jacinto River flood plain.  Another large population is found at Salt Creek west of Hemet.  An isolated population was discovered near Lake Elsinore in the late 1990’s  The northern portion of the crownscale range is within the San Jacinto Wildlife Area.  The majority of the range is unprotected.  The fate of this plant has for nearly two decades been closely tied to the San Jacinto River Flood Control and Improvement project.  This project seeks to control flooding along the river but would also substantially change the irregular flooding cycle that is necessary to maintain the alkali habitats along the river flood plain.  The San Jacinto River flood plain is a critical element of the western Riverside MSHCP.  Unfortunately the plan that was released for public review offered almost no certain protections for the crownscale or the flood plain habitat it is dependent on.