386 NORTH AMERICAN FLORA [VoruME 22 
Hypanthium not prickly; petals lacking. 
Stamens 2-4, not declined ; pistil 1. 
Perennials, with rootstocks; stigmas muricate-papillose ; leaflets toothed. 34. SANGUISORBA. 
Annuals or biennials, with tap-roots; stigmas brush-like; leaflets pecti- 
nate-pinnatifid. ' 35. POTERIDIUM. 
Stamens in the staminate flowers numerous and declined ; pistils 2. 36. POTERIUM. 
Hypanthium prickly. 
Petals wanting; spines of the hypanthium barbed; inflorescence dense. 37. ACAENA. 
Petals present; spines of the hypanthium hooked; inflorescence lax. 38. AGRIMONIA. 
34. SANGUISORBA L,. Sp. Pl. 116. 1753. 
Leafy perennial herbs, with thick rootstocks. Leaves odd-pinnate with adnate stipules 
and toothed leaflets. Flowers perfect or someof them pistillate, in dense spikes. Hypan- 
thium urn-shaped, contracted at the mouth, angled and usually winged. Sepals 4, petal- 
oid, deciduous, very concave. Petals none. Stamens in ours 4, opposite to the sepals. 
Pistils solitary; styles terminal; stigmas muricate-papillose; ovule solitary, suspended. 
Achenes dry, enclosed in the indurate 4-angled smooth hypanthium. 
Type species, Sangutsorba officinalis 1,. 
Stamens 2-3 times as long as the sepals; filaments flattened and dilated, especially towards the 
apex, 
Flowers white or greenish, heads at first lanceolate, acute, in age long-cylindric. 
Leaflets oblong, varying to ovate-oblong or lanceolate-oblong, 2-4 times as long as broad; 
midrib of the sepals thickened towards the apex. 1. S. canadensis 
Leaflets broadly oval, deeply cordate at the base, less than twice as long 
as broad; midrib of the sepals not thickened. 2. S. sttchensis. 
Flowers purplish in oblong obtuse spikes. 3. S. Menziestt. 
Stamens slightly if at all exceeding the sepals; filaments filiform; flowers 
purplish. 
Stamens decidedly exserted, leaflets rounded-ovate or oblong-ovate, rarely 
twice as long as broad, rounded at the apex. 4. S. microcephala. 
Stamens usually included; leaflets usually lance-oblong, obtuse or acutish, 
2-4 times as long as broad. 5. S. officinalis. 
1. Sanguisorba canadensis L. Sp. Pl. 117. 1753. 
Sanguisorba palustris Raf. Atl. Journ. 153. 1832. 
Poterium canadense A. Gray, Man.ed.5. 150. 1867. 
Glabrous perennial, with a strong rootstock; stem leafy, 3-20 dm. high, simple or 
branched above; leaves odd-pinnate, 1-6 dm. long, the lower with 7-17 leaflets, occasionally 
with foliaceous stipels, the upper more reduced; stipules adnate to the petioles, often 
leafy and oblique, coarsely serrate; leaflets with petiolules 5-25 mm. long, oblong, varying 
to ovate-oblong or lance-oblong, sharply serrate, obtuse at the apex, rounded, truncate, or 
somewhat cordate at the base, 1-6 cm. long, 5-30 mm. wide, firm, dark-green above, paler 
beneath; spike 3-15 cm. long, with the stamens 2 mm. thick, beginning to bloom at the 
base, therefore at first lanceolate and tapering to the apex; bracts lanceolate, pubescent, 
about equaling the buds; sepals oval, mucronate, white or greenish-white, 3 mm. long; 
filaments 6-8 mm. long, flattened and gradually dilated above, at the apex about 0.5 mm. 
wide, only a little narrower than the anthers; fruit puberulent, rounded rhombic-ovoid, 4- 
winged. 
TYPE LOCALITY: Canada. 
DISTRIBUTION : Swamps from Labrador and Newfoundland to Georgia and Michigan. 
ILLUSTRATIONS: Cornuti, Can. Pl. Hist. 174; Morison, Hist. p/. 18, f. 12; Britt. & Brown, 
Ul. Fl. f. 1964. 
2. Sanguisorba sitchensis C. A. Meyer, Fl. Ochot. 34. 1856. - 
Sanguisorba canadensis Cham. & Schlecht. Linnaea 2: 32. 1827. 
Sanguisorba canadensis latifolia Hook. Fl. Bor. Am. 1: 198. 1832. 
Poterium sitchense S. Wats. Bibl. Ind. 1: 303. 1878. 
Sanguisorba latifolia Coville, Cont. U. S. Nat. Herb. 3: 339. 1896. 
Glabrous perennial, with a strong rootstock; stem leafy, 2-12 dm. high, simple or 
branched above; leaves odd-pinnate, 1-10 dm. long, the lower with 11-21 leaflets, the 
upper more reduced; stipules rounded, coarsely toothed ; leaflets 2-7 cm. long, 1.5-5 cm. 
wide, coarsely serrate with ovate teeth, rather thin, paler beneath, rounded at the apex, 
those of the lower leaves deeply cordate at the base; petiolules often 1 cm. long; spike 
