Ehrharta erecta Lam.                                                                               Poaceae (Grass Family)                                                                                                                                        South Africa     Ehrharta

                                       April Photo

Plant Characteristics:  Perennial, erect, with flat blades 5-12 cm. long, 4-9 mm. wide and narrow panicles; spikelets, sessile to subsessile, 3.5-4.0 mm long, laterally compressed with 1 fertile floret and 2 large sterile, awnless lemmas below, enclosing the fertile floret, the first smooth, the 2^nd cross wrinkled, 3- or 5-nerved; rachilla disarticulating above the glumes, the fertile floret and sterile lemmas falling together; glumes ovate, obscurely keeled, the first 2mm. long, the second 3 mm. long; stamens 6.

Habitat:  Disturbed places below 200 m.  East San Francisco Bay; Northern south Coast (Santa Barbara and Ventura counties). Naturalized at Santa Barbara.        Tolerates a wide range of conditions.  On the coast it grows on warm, dry banks or in cool moist, deep shade.  It favors pure sand but will grow well in heavy soils too.  (Sigg, Jacob. “Triple Threat From South Africa” FREMONTIA, A Journal of the California Native Plant Society Vol. 31 No. 4 October 2003. pp. 21-28).

Name:  Named for J. Fredrich Ehrhart, German botanist, student of Linnaeus.  1742-1795.  Latin, erectus, erect. (Jaeger 95).

General:  Rare in the study area with only a few plants known and these clustered under the willows at 23^rd St.  (my comment).         Roberts in his 1998 A Checklist of the Vascular Plants of Orange County, California, does not list E. erecta, only E. calycina. (my comments).           Several South African plants pose a threat to the biodiversity of the California coast.  Three are particularly noxious, Cape Ivy, Delairea odorata; Ehrharta, Ehrharta erecta; and Yellow Oxalis, Oxalis pes-caprae.    Ehrharta erecta has been known in California for at least a half century but it has not received the attention of other invasive grasses such as Bermuda, crab and quack even though it has been invading wild lands for many years.  Urban areas as well as wild lands have been invaded and in San Francisco it moves down the streets, through block after block invading every planter and sidewalk crack.  It even takes over from other urban weeds such as dandelion, knotweed, foxtail barley, mallow and filaree.  Only Oxalis pes-caprae seems to be able to fight it off.  Ehrharta has several characteristics that give it an advantage over most plants; its seed can germinate in low light and it will grow undetected in the dark until it pushes through several feet of overlying plants.  Upon emerging from the dark ehrharta will quickly bloom and disperse its copious seed.  In the presence of other grasses and plants, ehrharta generates jointed prostrate or slightly ascending stems thus avoiding grazers and mowers and appearing eventually to deposit its seed.  The dense turf of ehrharta makes it difficult or impossible for other plants to germinate beneath it.  At present, the main infestations are along the coast due to its preference for moisture.  The best hope for control of this grass is biocontrol, however, genetic differences between plants must be studied to determine if a host-specific predator can control all plants.  (Sigg, Jacob. “Triple Threat From South Africa” FREMONTIA, A Journal of the California Native Plant Society Vol. 31 No. 4 October 2003. pp. 21-28).

Text Ref:  Hickman, Ed. 1253; Munz, Flora So. Calif. 965.

Photo Ref:  April-May 02 #4A, 8A.

Identity: by John Johnson.

First Found: April 2002.

Computer Ref:  Plant Data 538.

Plant specimen donated to UC Riverside in 2004. 

Last edit 8/7/05.   

                                                  April Photo