Aegilops species are not native to North America; however, Ae. triuncialis, Ae. cylindrica and Ae. ovata survive as adventitious species in the United States. Ae. triuncialis is the most widely spread Aegilops species in the world. This species has become a troublesome weed on the rangelands of California and Pennsylvania (van Slageren 1994). However, there is little or no awareness about its existence in Pennsylvania (Hartwig N: pers commun). Ae. cylindrica is also troublesome in fields and pastures. Its growth on the edges and within wheat fields is also troublesome. Gene transfer between wheat (Triticum aestivum) and Ae. cylindrica in the field may pose a potential problem since Ae. cylindrica may receive traits, such as herbicide resistance, from transgenic wheat cultivars through natural introgressive hybridization (Seefeldt et al. 1998; Zemetra et al. 1998). The geographical distribution of Ae. cylindrica was surveyed in 1993 by USDA-ARS (http:// www.janr.unl.edu/jgg/maps/). Ae. cylindrica is a serious weed in Northern Oregon, but not so much problematic in California. The distribution of Ae. triuncialis in North America is not well documented. However, information from herbarium specimen indicates a wide distribution area in the central regions of California. We had an opportunity to collect 17 populations of Aegilops species in California and Oregon from 28 June to 6 July, 1999, which is described in this report.

The collection sites and areas covered are presented in Table 1 and Fig. 1.

Aegilops triuncialis (1-6)
In the ranges of south of Milton and San Andreas, California, Ae triuncialis was found in massive stands. At Winters, however, it was found in dry and open ground between a dismantled railroad track and forage-road. Ae. triuncialis is widely distributed at altitude ranges of 300 m to 1000 m at the Experimental Station, University of California at Hopland. Ae. triluncialis is troublesome weed because of its narrow leaves and barbed spikes, which are not preferred by sheep for grazing. Burning is applied to reduce population size of Ae. triuncialis at the Experimental Station. We also found Ae. triuncialis on a southwest facing road-cut and a slope above the road-cut located three miles northeast of Nevada City. We did not find Ae. triuncialis in Oregon.

Aegilops cylindrica (7-16)
California was not widely infested with Ae. cylindrica. In Crestline, we found Ae. cylindrica growing together with wheat plants at the roadside. At Santa Barbara, Ae. cylindrica survives at the edge of an old pasture, that used to be a cattle-feeding lot and now abandoned as grassland. It is thought that Ae. cylindrica might have spread as a contaminant of cattle feed. There is herbarium specimen collected in the Santa Cruz Island, near Santa Barbara (van Slageren 1994). Ae. cylindrica was found at roadsides and edges of grasslands from Yreka to Montague in the Siskiyou county. At the east of Montague, it was found in massive stands in a grassland leading to pastures. There is a report that Ae. cylindrica was found at Tulelake (Waines JG: pers commun), but we were unable to find it. In California, the distribution of Ae. cylindrica was restricted to the roadsides and edge of pastures.

Wasco, Gillian and Morrow are known to be the most infested Counties of Ae. cylindrica in Northern Oregon. As summarized in Table 1, Ae. cyiindrica was found at the edges of wheat and barley fields and feed lots. At the edge of wheat field of Condon, we could easily find hybrid plants between wheat and Ae. cylindrica (Fig. 2). Hybrid plants were vigorous and their spikelets were sterile. Hybrid plants were also found in a wheat field at the corner of Ella Road and Rietniann Lane of lone, Morrow County. In Northern Oregon, Ae. cylindrica survives at the edge of wheat field and invades into wheat field where natural hybrids are formed. It means that Triticum and Aegilops are in the process of evolution.

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