136 POLYGONACEAE. 



V 



reduced above; Glowering branches slender, erect very long (% to iy 2 ft-), 

 naked or with a Lanceolate or ovate leaf subtending some or all of the^ remote 

 whorls; pedicels ;is long :is, or rather shorter than the fruit, tumidly jointed 

 near the base and geniculate; fruit about 1 line long, the inner sepals oblong 

 with callous grains mostly 3 and smooth. 



Naturalized: abundant in lowlands about San Francisco Bay and southward 

 to Southern California. 



5. R. salicifolius Weinm. Willow Dock. Commonly tufted, 2 ft. high; 

 leaves 1% to 5 in. long, plane, glaucous, lanceolate, acute at both ends; flower- 

 ing branches short (2 or less commonly 4 in. long), the lateral mostly divari- 

 cate; whorls dense, crowded, leafless, or 1 or 2 lower whorls remote and leafy; 

 pedicels rather shorter than the fruit, jointed near the base and recurved but 

 not geniculate; inner fruiting sepals triangular or triangular-ovate, pink-red, 

 1 or 2 lines long, the white callous grains variable in number, smooth or pitted. 



Wet places in valley lands, widely distributed. Sometimes called "White 

 hock" and readily recognized by its whitish willow-leaved foliage. 



6. R. pulcher L. Fiddle Dock. Stem slender but rigid, widely parted 

 into zigzag branches; leaves oblong or fiddle-shaped, 3 to 5% in. long, 

 petioled; flowering branches simple, divaricate, sparsely leafy, the dense 

 whorls remote or at least distinct, red-brown in fruit; pedicels about equaling 

 the fruit, tumidly jointed in the middle; inner fruiting sepals with 5 to 10 

 awn-like teeth on each side; callous grains 1 to 3. 



Naturalized weed; waysides and vacant lots in towns, common. 



7. R. obtusifolius L. Bitter Dock. Tall, slender, 3 ft. high or more; 

 leaves ovate-oblong to oblong-lanceolate, somewhat undulate, acute or obtuse, 

 truncate or cordate at base, 6 in. long or less, long-petioled; flowering branches 

 in a rather strict panicle, leafless or with a few little-reduced leaves at the 

 base; whorls loose, not crowded, the lower remote, pedicels slender, 1 to 2 times 

 as long as the fruit, tumidly jointed toward the base; inner fruiting sepals 

 ovate-deltoid, 1% to 3 lines long, with 3 to 5 thin triangular or subulate 

 teeth on each side; grain 1 only or with 2 other small ones. 



Introduced species in low lands about San Francisco Bay. 



8. R. persicarioides L. Golden Doc*. Stems soft and fistulous (at least 

 below), prostrate or erect, seldom more than 1 ft. high; herbage yellowish 

 green, minutely pubescent; leaves oblong or lanceolate, truncate or subcordate 

 at base, acute at apex, a little undulate, 2 to 4 in. long, rather short-petioled; 

 flowering branches with scattered subequal leaves, the whorls mostly crowded 

 or the lower remote; pedicels very unequal, tumidly jointed at base; inner 

 fruiting sepals % to 1% lines long, acutely produced at apex with 2 or 3 awn- 

 like teeth on each side; callous grains 3; fruit almost bur-like. — (R. maritimus 

 of Bot. Cal.) 



Wet places by lakes or streams or in marshy lands. 



7. POLYGONUM L. Knotweed. 

 Herbaceous or suffrutescent plants, some of them hydrophytes. Leaves entire, 

 alternate, with scarious sheathing stipules ("sheaths"), these entire, ciliate 

 or lacerate. Flowers white, red or greenish, on jointed pedicels. Calyx red, 

 white, or sometimes greenish, in all ours 5-cleft or -parted, the divisions erect 

 in fruit. Stamens 4 to 9. Styles 2 or 3. Achene lenticular or triangular, 

 enclosed IB the fruiting calyx. Embryo curved, lying in a groove at an angle 

 of the endosperm. (Greek polus, many, and gonu, knee, on account of the 



DOdose Zigzag stem of many species.) 



