194 ROSACEAE (ROSE FAMILY) 



2. A. striata Michx. Erect, subsimple up to the inflorescence, 3-15 dm. high, 

 softly pubescent, the hairs incliniiig to be appressed ; leaflets mostly narrowed 

 to a point, somewhat costate ; fruiting-calyx strongly deflexed ; the hooks rela- 

 tively short and connivent or scarcehj spreading. {A. Eupatoria Man. ed. 6, in 

 part, not L.; A. BriWmiana Bicknell.) — Damp woods, alluvial soil, etc., Nfd, 

 to Sask., s. to W. Va., 111., Neb., S. Dak., and N, Mex. (Eurasia.) 



3. A. m6llis (T. & G.) Britton. Grayish-pubescent, 6-15 dm. high ; leaflets 

 oblong, mostly obtuse, soft to the touch on both surfaces ; fruit broadly top- 

 shaped, the hooks borne on a broad disk, the outer widely spreading. {A. 

 piibescens WaHr. ?) — Open woods, dry ground, etc., Mass. to N. C, and westw. 



4. A. microcarpa Wallr. Small, subsimple, mostly 3-5 dm. high ; leaflets 

 obovate, soft-tome ntose beneath, sparingly appressed-pubescent or subglabrous 

 above ; friiitiiig calyx nmch as in the last but smaller. (A. pumila Muhl., 

 inadequately characterized.) — Woods, etc.. Pa. to Fla. and Tex. 



5. A. parvifl5ra Ait. iStem hirsute, 7-12 dm. high, leafy ; leaflets numerous, 

 narrow, with many smaller intermediate ones of 2 or 3 different sizes ; fruiting 

 calyx small (4-5 mm. long), abruptly deflexed at maturity from an ascending 

 pedicel ; outer hooks widely spreading. — Chiefly in sandy and alluvial soil, Ct. 

 to Ga., westw. to Ont., Kan., and La. 



6. A. rostellata Wallr. Slender, 4-8 dm. high ; stem nearly glabrous, rough- 

 ish ; leaflets few, obovate ; fruiting calyx small, almost hemispherical, not deeply 

 furrowed, the hooks small, the longest shorter than the connivent calyx-lobes. 

 (A. striata Bicknell, not Michx.) — Rocky woods, alluvium, etc., Ct. to Ga., and 

 wrestw. 



22. SANGUIS6RBA [Rupp.] L. Burnet 



Calyx with a top-shaped tube, constricted at the throat, persistent ; the 4 

 bi'oad petal-like spreading lobes imbricated in the bud, deciduous. Petals none, 

 ^aniens 4-12 or more, with flaccid filaments and short anthers. Pistils 1-3 j 

 the slender terminal style tipped with a tufted or brush-like stigma. Achene 

 (commonly solitary) inclosed in the 4-angled dry and thickish calyx-tube. Seed 

 suspended. — Chiefly perennial herbs, with unequally pinnate leaves, stipules 

 adherent to the petiole, and small often polygamous or dioecious flowers 

 crowded in a dense head or spike at the summit of a long and naked peduncle, 

 each bracteate and 2-bracteolate. (Name from sanguis, blood, and sorbere, 

 to drink up, to absorb, from reputed styptic properties in folk-medicine.) Pote- 

 RiuM L., in part. 



* Stamens 4 ; leaflets 2-5 cm. long. 



1. S. canadensis L. (Canadian B.) Stamens long-exserted, club-shaped, 

 white, as is the whole of the elongated and cylindrical spike; stem 3-16 dm. 

 high ; leaflets numerous, ovate or oblong lanceolate, coarsely serrate, obtuse, 

 heart-shaped at base, as if stipellate ; stipules serrate. (Poterium Gray.) — 

 Bogs and wet meadows. Lab. to mts. of Ga., w. to Mich. 



2. S. OFFICINALIS L. In habit similar to the preceding; spikes dense, 

 ovoid, brownish- or purplish-red. — Established in low fields near coast of Me.; 

 also reported from Minn. (Adv. from Eurasia.) 



* * Stamens numerous; leaflets 8-15 mm. long. 



3. S. MINOR Scop. (Garden B.) Stamens 12 or more in the lower flowers 

 of the globular greenish head, with drooping capillary filaments, the upper flow- 

 ers pistillate only ; stems 3-6 dm. high ; leaflets small, ovate, deeply cut. {Po- 

 terium Sanguisorba L.) — Locally established in grassy places, cultivated 

 grounds, etc., Me. to Md. and w. N. Y. (Adv. from Eurasia.) 



* 



23. r6SA [Tourn.] L. Rose 



Calyx-tube urn-shaped, contracted at the mouth, becoming fleshy in fruit. 

 Petals 5, obovate or obcordate, inserted with the many stamens into the edge 

 of the hollow thin disk that lines the calyx-tube and within bears the numerous 



