218 HALORAGE^E. callitkiche. 



stamen with large thick filament and rather large 2-celled anther : fruit 

 oval or somewhat 4-sided, 2-3 lines long ; stigma persistent. In ponds and 

 marshes, Alaska to California, the Eastern States and Europe. 



Var. fluviatilis Hart. Larger; leaves 2-3 inches long, grass-like, in 

 closely crowded whorls Oregon to Canada and Sweden. 



H. tetraphyllum L. f Suppl. 81. Stems 10-12 inches high, leaves in 

 whorls of 4 or 6, oval to obovate, often feather-veined ; fruit less than 2 

 lines long. Alaska, perhaps northern Washington. 



H. montaua Ledeb. Reichenb. Incon. Bot. i, 71. Stems 2-4 inches high; 

 leaves 1-nerved, linear mucronate, in whorls of 5-6, 4-6 lines long : flowers 

 often monoecious : fruit almost oval, a line or more long, minuteiy granu- 

 late. In wet turfy places, Alaska to Washington. 



2 CALLITRICHE L. Gen. n. 13. 



Small, mostly aquatic, herbs with opposite entire leaves with- 

 out stipules and small axillary monoecious flowers without pet- 

 als. Calyx adherent to the ovary the limb very short or obso- 

 lete. Petals none. Stamen one with slender filament and cor- 

 date 4-celled anther. Ovary 4-celled, with 2 filiform styles. 

 Fruit 4-celled, flattened and emarginate, 4-seeded, indehiscent, 

 the cells separating at maturity into 1 -seeded nutlets. 



* Emersed leaves obovate-spatulate> 3-nerved, the submersed 

 linear, (all uniform and narrow in terrestrial forms) : carpels connate. 



-«- Fruit pedicillate, wing-margined ; bract 3 none 



C. marginata Torr Pacif R. Rep. iv, 135. Stems slender, branch- 

 ing, rooting in the mud growing in water: submersed leaves linear, 1- 

 nerved, running gradually into the emersed oblanceolate or spatulate 3- 

 nerved ones, or the terrestrial form with linear spatulate 3-nerved leaves 

 4-5 lines long : peduncles about two-thirds as long as the leaves, spread- 

 ing or reflexed : styles as long or shorter than the fruit reflexed deciduous : 

 fruit broader than long with conspicuous membranaceous wings and di- 

 vergent lobes. From Arizona and California to The Dalles, Oregon. 



C. sepulta Watson Proc. Am. Acad, xiv, 298. Terrestrial, prostrate 

 and rooting in the mud: the numerous narrowly linear leaves 2-3 lines 

 long: fruit broader than long emarginate at both ends, the thick carpels 

 with acute divergent margins, on stout pedicels 1-3 lines long soon de- 

 flexed and buried in the soil : stigmas elongated, reflexed, soon deciduous. 

 Oregon. (Hall 1871.) 



C. verna L. Sp. i, 2. Perennial, with elongated stems and floating 

 rosulate obovate often emarginate leaves which are more or less narrowly 

 petioled the submerged ones from spatulate to linear: sometimes terres- 

 trial and rooting with short linear leaves : bracts often longer than the 

 fruit rarely wanting: stigmas erect or spreading, usually snorter than the 

 fruit, deciduous: fruit oblong flat on the face mostly with a small apical 

 notch and narrow apical wings the grooves between the lobes deep. Com- 

 mon from Alaska to California, the Eastern States and Europe, Asia and 

 S. America. 



C. heterophylla Pursh. Perennial with elongated stems and obovate 

 floating leaves, the submerged ones linear -lanceolate, long acuminate, 

 4-8 lines long, sometimes terrestrial and rooting, with short linear leaves: 

 stigmas longer than the fruit persistent : fruit obovate, broader than long, 

 with a deep broad notch at the apex, thick, almost ventricose near the 

 base, the lobes obtusely angled, with a small groove between them, wing- 



