802 HALORAGIDACEAE (WATER MILFOIL FAMILY) 



* * Fruit slender-pediceled. 



4. G. f ilipes Spach. Nearly smooth ; stem slender, 6-12 dm. high ; leaves 

 linear, mostly toothed, tapering at base ; branches of the panicle very slender, 

 naked ; fruit obo void-club-shaped, 4-angled at the summit. (G. Michauxii 

 Spach.) Open places, S. C. and Fla. to Tenn. and Okla. ; also said to occur 

 from Va. to O. and Kan., a range in need of further confirmation. 



6. STENOSlPHON Spach. 



Calyx prolonged beyond the ovary into a filiform tube. Fruit 1-celled, 

 1-seeded. Habit of Gaura. (From <rrej>6s, narrow, and <rl<pwv, a tube.) 



1. S. Iinif61ius (Nutt.) Britton. Slender, 6-12 dm. high, glabrous, leafy ; 

 leaves narrowly lanceolate to linear, pointed, entire, much reduced above ; 

 flowers numerous in an elongated spike, white, 1.2cm. long; fruit pubescent, 

 ovoid, 8-ribbed, 2.5-3 mm. long. (S. virgatus Spach.) Gravelly hills and dry 

 prairies, e. Kan. to Col. and Tex. 



7. TRAPA L. WATER NUT. WATER CALTROP 



Calyx-tube short, inclosing the base of the ovary ; limb 4-parted, the seg- 

 ments persistent and becoming spinescent. Fruit indehiscent, large, with 2-4 

 strong spines, 1-celled, 1-seeded. Aquatic plants, with opposite or whorled 

 leaves, the upper crowded, with inflated petioles, rhombic, coarsely toothed, the 

 submersed remote, with capillary segments ; flowers borne among the floating 

 leaves. (Name abridged from calcitrapa, a caltrop, in allusion to the spreading 

 points of the fruit.) 



1. T. NATANS L. (WATER CHESTNUT.) Fruit 4-horned ; seed edible. Quiet 

 streams and ponds, Middlesex Co., Mass. ; Schenectady Co., N. Y. (Introd. 

 from Eurasia.) 



8. CIRCAEA [Tourn.] L. ENCHANTER'S NIGHTSHADE 



Calyx-tube slightly prolonged, the end filled by a cup-shaped disk, deciduous ; 

 lobes 2, reflexed. Fruit indehiscent, small and bur-like, bristly with hooked 

 hairs, 1-2-celled ; cells 1-seeded. Low perennials, with opposite leaves on 

 slender petioles, and small whitish flowers in racemes, produced in summer. 

 (Named for Circe, the enchantress.) 



1. C. lutetiana L. Tall (3-9 dm. high); leaves ovate, tending to ovate- 

 oblong, mostly rounded at the base, of rather firm texture, slightly toothed ; 

 bracts none ; hairs of the roundish pyriform ^-celled fruit bristle-like (rarely 

 wanting). Common in dry open woods, N. S. to Ont., and south w. (Eu.) 



2. C. intermedia Ehrh. Lower, 2-4 dm. high ; leaves thin, ovate, the 

 middle and upper more or less cordate, the teeth salient; minute bracts 

 usually present ; petals as long as the calyx ; fruit nearly as in the preceding. 

 Deep shade, e. Que. to Ont., la., and Tenn. (Eu.) Not always well marked. 



3. C. alpina L. Low (7-20 cm. high), smooth, weak; leaves heart-shaped, 

 thin, shining, coarsely toothed ; bracts minute ; petals usually shorter than the 

 calyx ; hairs of the obovoid l-celled fruit soft and slender. Deep woods, Lab. 

 to Alaska, s. to Ga., Ind., Mich., n. e. la., and S. Dak. (Eu.) 



HALORAGIDACEAE (WATER MILFOIL FAMILY) 



Aquatic or marsh plants {at least in northern countries'), with the incon- 

 spicuous symmetrical (perfect or unisexual) flowers sessile in the axils of 

 leaves or bracts, calyx-tube adherent to the ovary, which consists of 2-4 more 

 or less united carpels (or in Hippuris of only one carpel), the styles or sessile 

 stigmas distinct. Limb of the calyx obsolete or very short in fertile flowers. 



