(275) 



'* Yellow dock." Native of Europe, now 

 naturalized. 



3. R. CONGLOMERATUS Murray. Calyx valves 

 entire, bearing callosities; leaves lanceolate, 

 tlie lower leaves cordate, slightly undulate. 

 U . Common. Spring. 



Also called "yellow dock, "native of Europe, 

 and at present naturalized. 



4. R. OBTUSiFOLius L. Calyx valves with 

 slender awn-like teeth and bearing callosities. 

 U , Contra Costa. Spring. 



7. R. ACETOSELLA L. Dioecious. Valves 

 without callosities; leaves hastate. — U- Com- 

 mon. Spring. ''Sheep-sorrel." 



2. Polygonum L- Knot-c4rass. 

 Perigonium 5, sometimes 4-phyllous. Sta- 

 mens S-S^^ngle or in pairs opposite to the 

 sepals. Styles 3, sometimes 2; stigmas capi- 

 tulate. Fruit a 3-cornered or lenticular akene, 

 enclosed in the persistent perigonium. 



1. P. PARONYCHIA Cham. & Schlecht. Flow- 

 ers in leafy spikes; leaves lanceolate, with re- 

 volute margins; flowers x^ale, veined with green. 

 71 . San Francisco. Simimer. 



2. P. AYICULARE L. Flowers axillary, pale. 

 — 0. Common. Spring, Summer. 



3. P. Californicum Meissn. Flowers spi- 

 cate; bracts foliaceous, each bract containing 



