42 POLYGONE^E. 



7. P. Persicaria, L. Much like the last but the sheaths and bracts 

 conspicuously ciliate: leaves less acuminate, subsessile: spikes shorter 

 and erect: fl. rose-color: achenes often triquetrous. Not common. 



-i Perennials, either aquatic or of wet places. 



8. P. acre, HBK. Decumbent, rooting at the lower joints, 2 5 ft. 

 high; herbage light green, pellucid-punctate and acrid, glabrous or a little 

 scabrous: leaves lanceolate, acuminate, short-petioled; sheaths bristly- 

 ciliate: spikes narrow and lax, 13 in. long, erect: sepals greenish and 

 glandular-dotted, 1 line long: stamens 8: achene commonly triquetrous. 

 Very common in marshy places, along streamlets, etc. June Nov. 



9. P. Hartwrightii, Gray. Stems stout and simple, rooting at the 

 decumbent base, above equably leafy to the summit; herbage more or 

 less strigose-hirsute : leaves broadly lanceolate, acute, 2 7 in. long, on 

 very short petioles; stipules with an abruptly spreading foliaceous bor- 

 der: fl. rose-red, in a dense ovate or oblong terminal spike: stamens 5: 

 style 2-cleft: achene lenticular. In low ground; not common. 



10. P. Mnhlenbergii, Wats. Stoutish, erect, 23 ft. high, leafy 

 throughout; scabrous with short appressed or glandular hairs, with more 

 or less of a softer pubescence: leaves broadly lanceolate, narrowly acumi- 

 nate, 47 in. long, on petioles of nearly 1 in. ; sheaths with no spreading 

 margin: spikes 1 or 2, elongated and narrow, 1 3 in. long: fl. and fr. as 

 in the last. Shore of the lakelet in front of the U. S. Marine Hospital, 

 San Francisco; rare in California. 



11. P. a in phi hi u in . L. Aquatic and with floating leaves, or geniculate 

 and rooting in the mud along the shores of ponds and lakes; herbage 

 glabrous or nearly so: leaves elliptical or oblong, obtuse or acutish, very 

 smooth and shining above, 2 5 in. long, on petioles half as long: spike 

 mostly solitary, dense, ovate or oblong, 1 1^ in. long: fl. rose-color: fr. 

 lenticular. Common in mountain lakes. 



* * * * Twining or climbing annuals with broad leaves, and flowers in loose 

 axillary panicles or racemes; achenes triquetrous. 



12. P. CONVOLVULUS, L. Twining or trailing, 13 ft. high, minutely 

 scabrous: leaves 12 in. long, hastate-cordate, acuminate: fl. in axillary 



'interrupted racemes: fruiting perianth 1^2 lines long, equalling the 

 somewhat opaque granulate -striate achene. A weed in cultivated lands; 

 native of Europe, not yet prevalent in California, but already met with 

 near Berkeley. July Sept. 



2. RUMEX, Pliny (DooK. SORREL). Coarse perennials (rarely 

 annual or biennial), with leafy stems, and cylindrical obliquely truncate 

 scarious stipules; the small green or reddish perfect or unisexual flowers 

 fascicled or verticillate, forming panicled racemes. Perianth of 6 nearly 



