SAGITTARIA AND LOPHOTOCARPUS. 33 
(1848). SS. sagittifolia of Amer. authors, not Linn. 
S. sagittifolia, var. variabilis Micheli in DC. Monog. 
Phan. 3: 69 (1881), in part, not 8. longiloba Engelm. 
8. variabilis var. angustifolia Engelm. in A. Gray, 
Man. Ed. 5, 493 (1867). &. variabilis var. diversi- 
folia, Engelm. in A. Gray, Man. Ed. 5, 493 (1867). 
S. variabilis var gracilis Engelm. in A. Gray, Man. 
Ed. 5, 493 (1867). SS. hastata Pursh, 1. c. &. va- 
riabilis var. hastata Engelm. in A. Gray, Man. Ed. 5, 
493 (1867). WS. variabilis var. hastata form a, and 
in part forms 6 and c, Macoun, Cat. Can. Pl. 4: 77, 78 
(1888). S. obtusa Willd. Sp. Pl. 4: 409 (1806). S. sag- 
ittifolia var. macrophylla, and var. vulgaris Hooker Fl. Bor. 
Amer. 2: 167 (1840). S. Chinensis Parish, Zoe, 1: 122 
(1890). WS. Sinensis Brandegee, Zoe, 4: 217 (1893), 
not Sims. 
Monoecious, with the lower verticils fertile, or dioecious; 
scape 1 to 12 dm. high, angled, simple or branched; flow- 
ers large, 2 to 4 cm. wide, the petals white; stamens 
numerous, 25 to 35; fertile pedicels shorter than the ste- 
rile; bracts sometimes connate in the upper verticils, acute, 
acuminate, or obtuse, not scarious; achenium broadly 
winged on both margins, 2.5 to 3.5 or rarely 4 mm. long, 
with a lateral horizontal or curving beak } to } its length, 
sides usually smooth, or with a costate angle curving down- 
ward from the base of the beak, rarely with a subepidermal 
resin passage on each face.— An extremely variable species, 
extending from Nova Scotia to British Columbia, south 
along the Pacific Coast to California, and throughout the 
region east of the Rocky Mountains to Mexico and 
Florida. —Plates 3 to 7. 
The species is a complex one on account of its wide geo- 
graphical distribution and varying habitat. After an ex- 
amination of nearly all the available material, the species 
seems best divided into forms instead of varieties, of which 
I recognize five. These merge into one another, so that it 
is difficult to draw hard and fast lines between them. The 
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