ZANTHOXYLACEiE. 67 



Mountain woods. Can. Mass. N. Y. and Penn. June. %.—Sca}je 3—5 inches 

 long. Flowers large, white, with red veins, drooping. Petals slightly emargi- 

 nate. This is the Shamrock of the Irish. The expressed juice yields binoxate 

 of potash. Common Wood Sorrel. 



2. O. violacea Linn. : bulb scaly; scape umbelliferous, 3 — 9-flowered ; 

 flowers nodding ; leaves ternate ; leafets obcordate, smooth ; styles shortei 

 than the outer stamens. 



Rocky woods. Can. to Geor. W. to Miss, and Texas. May, June. %.— 

 Scajje 4 — 6 inches high. Flowers violet, umbelled, with the petals obovate and 

 sometimes slightly emarginate. Violet Wood Sorrel. 



• ** Cav.hscent. 



3. O. corniadata .Linn. : pubescent ; stem rooting, decumbent, branched ; 

 peduncles 2-flowered, shorter than the leaves ; leaves ternate ; leafets ob- 

 cordate ; petals obovate, emarginate ; styles as long as the inner stamens. 

 O. cm-niculata var. Mich. 



Woods. Can. to Car. W. to Miss, May— Aug. %.—Stem 6—10 inches 

 long. Flowers small, yellow. It is distinguished chiefly by its habit ; but the 

 plant of American authors may after all be only a variety of the next. 



Decumbent Wood Sorrel. 



4. O. stricta Linn. : hairy ; stem erect, sometimes procumbent, branched ; 

 peduncles 2 — 6-flowered, longer than the leaves ; leaves ternate ; leafets 

 obcordate ; petals obovate, entire ; styles as long as the inner stamens. 



Sandy Fields. Can. to Louis. W. to the Rocky Mountains. May— Aug. %. 



Stem 4 — 12 inches high. Flowers small, yellow, 4 — G in an umbel. 



Upright Wood Sorrel. 



Order XXXIL ZANTHOXYLACE^.— Zanthoxyls. 



Flowers diclinous, regular. Calyx in 3, 4, or 5 divisions. 

 Petals as many as the sepals, rarely none, convolute. Stamens 

 as many or twice as many as tlie petals. Ovaries as many as 

 the petals, sometimes fewer; styles more or less combined. 

 Fruit either baccate or membranous, sometimes consisting of 

 several drupes or 2-valved capsules. Seeds solitary or in pairs, 

 with fleshy albumen. — Trees or shrubs. Leaves without sti- 

 pules, usually marked with pellucid dots. 



1. ZANTHOXYLUM. ivwm.— Prickly Ash. 

 (From the Greek ^avdog, yellow, and |vXoi/, wood.) 



Polygamo-dioecious. Sepals 3 — 5, small. Petals longer 

 than the sepals, or none. Stamens and carpels as many as the 

 lobes of the calyx, 1 — 2-seeded. 



Z. Americanum Mill. : prickly ; leaves pinnate ; leafets in 4 — 5 pairs, 

 ovate, obsoletely serrate, equal at base ; petioles terete, unarmed ; prickles 

 stipular; flowers in short axillary sessile umbels. Z. fraxineum Willd. 

 Z. ramijiorum Mich. 



