82 BUCKWHEAT FAMILY 



dom more than \ x / 2 ft. high. Leaves usually floating, oblong 

 to lanceolate, acute, 3 to 6 in. long, 1 to 2 in. wide, long- 

 petioled. Flowers bright rose-color, in a dense oblong raceme 

 which is x / 2 to 2 in. long. — Usually growing in water but 

 sometimes on muddy banks where the stems become erect 

 and more pubescent. It has been collected in the Hetch 

 Hetchy meadows. 



4. P. persicaria L. Lady's Thumb. An introduced annual 

 with usually erect stems, 1 to 5 ft. high, leafy throughout. 

 Leaves lanceolate, 1 to 4 in. long, J4 to 1 in. wide, short- 

 petioled. Flowers pink, in dense oblong racemes (}/ 2 to 1% 

 in. long) terminating short branchlets. — In moist situations 

 but not in water; Yosemite Valley. 



5. P. shastense Brewer. A low spreading perennial with 

 numerous leafy and woody twigs inclined to creep along 

 the ground. Leaves linear, rather less than y 2 in. long, acute. 

 Flowers in the lower leaf-axils, rose-color or nearly white. — 

 Only near timber-line on the higher peaks. 



6. P. aviculare L. Yard Grass. A green glabrous annual 

 with prostrate wiry stems often several feet long. Leaves 

 oblong, acute, % to Y\ in. long. Flowers from most of the 

 axils, erect. — An European weed, naturalized around some 

 of the settlements. 



7. P. minimum Wats. Stems scurfy, reddish, y^ to 1 ft. 

 high, leafy to the summit. Leaves mostly obovate or broadly 

 oblong, broad at apex but abruptly short-pointed, l /^. to 24 in. 

 long, nearly sessile. Flowers erect. Akenes black, shining, 

 slightly exserted from calyx. — A high-altitude species found 

 in moist soil on Mt. Watkins at 6900 ft. alt., also (by Miss 

 Helen D. Geis) in Yosemite Valley, where doubtless carried 

 down by streams. 



8. P. ramosissimum Michx. Stems 1 or 2 ft. high, almost 

 woody, ridged, the few branches ascending. Leaves linear- 

 oblong, y 2 to l x / 2 in. long, narrowed to each end, short- 

 petioled. Flowers several in each of the axils, on erect 

 pedicels. Stamens 3 to 6. Akenes granular, not shining. — 

 Yosemite Valley, etc. 



9. P. tenue Michx. Much more slender than no. 8 and 

 only 1 ft. or less high, the leaves mostly narrowed to a 

 slender tip; stamens 8. — Reported from "Yosemite and above." 



10. P. douglasii Greene. Stems slender, y 2 to l l / 2 ft. high, 

 with very few branches. Leaves linear-oblong, y 2 to 2 in. 

 long, sharply pointed, sessile. Flowers remote, usually only 



