. The Canadian field-naturalist. 72 The Canadian Field-Naturalist Vol. 94 1959). The only collection from the area west of the Continental Divide is that from Utah (Fernald 1932; Haynes 1974; Cronquist et al. 1977). In British Columbia we found it in the lower Eraser Valley (Kawkawa Lake near Hope) and in the Rocky Mountain Trench (Windermere and Columbia lakes). It occurs with Heteranthera dubia in Kawkawa Lake, and with Megalodonta beckii in both Windermere and Columbia lakes. Potamogeton strictifolius is related to P. friesii but is distinguished by its acute leaf tips and revolute leaf mar
. The Canadian field-naturalist. 72 The Canadian Field-Naturalist Vol. 94 1959). The only collection from the area west of the Continental Divide is that from Utah (Fernald 1932; Haynes 1974; Cronquist et al. 1977). In British Columbia we found it in the lower Eraser Valley (Kawkawa Lake near Hope) and in the Rocky Mountain Trench (Windermere and Columbia lakes). It occurs with Heteranthera dubia in Kawkawa Lake, and with Megalodonta beckii in both Windermere and Columbia lakes. Potamogeton strictifolius is related to P. friesii but is distinguished by its acute leaf tips and revolute leaf margins (Voss 1972; Haynes 1974). The plants look like a miniature of Potamogeton robbinsii. Their leaves are stiff, deep olive green in color, and often two-ranked. The growth habit of P. strictifolius is also similar to that of P. robbinsii; the plants grow in dense clumps covering lake bottoms. Collections seen: Windermere Lake, southern end, A. &0. Ceska925. 13 September 1978 (V); Columbia Lake, northern end, A. &0. Ceska 958, 13 September 1978 (V); Hope, Kawkawa Lake, A. Ceska & B. Mit- chell 1372, 23 September 1978 (V). *Tillaea erecta, Erect Pigmy-weed This species is known from California, Arizona, and southwestern Oregon, and it also occurs in South America in Chile (Britton and Rose 1905; Munz and Keck 1959). It is an annual species that grows in chaparral (McPherson and Muller 1969), vernal pools (Holland and Jain 1977), and on coastal cliffs. In our area, T. erecta was found on the coastal cliffs of Sidney Island and on Rocky Point west of Victoria. We also found T. erecta as a species new to the flora of Washington; it was collected on two locations on San Juan Island. In all of these localities T. erecta occurs along the coast, at the edge of till deposits over basal- tic rocks. All of these sites stay wet in spring because of seeping water. Tillaea erecta is a diminutive succulent with oppo- site leaves and tetramerous flowers (Figure 3). Collections see
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