338 HALOEAGE^. 



latter being the type of CE. dentata. The var. crtjciata Wats, has 

 narrowly ohovate or oblong petals one-half as large. 



9. CIRC/EA L. Enchanter's Nightshade. 



Low slender perennials with thin opposite petioled leaves. Flowers 

 small, white, in terminal and lateral racemes. Calyx-tube slightly 

 produced beyond the ovary, the base nearly filled by a cup-shaped 

 disk, deciduous; lobes 2, reflexed. Petals 2, obcordate. Stamens 2, 

 alternate with the petals. Ovary 1 or 2-eelled, each cell l-ovuled. 

 Fruit indehiscent, pear-shaped and bristly with hooked hairs. (Circe, 

 sea-nymph, daughter of the Sun and of Perse.) 



1. C. Pacifica Asch. & Mag. Stem from a short rootstock, 

 usually simple, 6 to 14 in. high; glabrous; leaves orbicular to mostly 

 ovate, obtuse to cordate at base, acuminate, obscurely repand- 

 denticulate or almost entire, 1 to 2 in. long on petioles f to 1 in. long; 

 racemes bractless; flowers i line long; calyx white, with a very short 

 tube; fruit rather less than 1 line long, the bristle-like hairs curved 

 at tip, 1-celled, 1-seeded. 



Deep shades of woods. Collected in the Bay Region only at 

 Lagunitas Creek, Marin Co., J. P. Moore, July 4, 1878; ranging 

 northward through Mendocino and Humboldt to Mt. Shasta, Jepson, 

 thence southward in the Sierra Nevada to Placer Co., Cosumnes, 

 Hansen, Yosemite Vallej', and Marble Fork of the Kaweah. Bather 

 rarely collected in California. 



70. HALORAGEi^. Water-Milfoil Family. 



Perennial aquatic herbs, the leaves (in ours) in whorls. Flowers 

 sessile in the axils of leaves or bracts, perfect or unisexual. Calyx- 

 tube coherent with the ovary, the limb very short or obsolete. Petals 

 small, 2 to 4, or none. Stamens 1, 4, or 8. Ovary 1 to 4-celled; 

 stigmas 1 to 4. Fruit a 1-seeded indehiscent nutlet, or 4-lobed and 

 splitting into 4 nutlets. 



Leaves all entire; flowers perfect; stamen 1; ovary I-celled .... 



1. HiPPUEIS. 



Immersed leaves capillary dissected; flowers polygamous; stamens 4 or 8; 

 ovary 4-celled . ". .... 2. Myriophyllttm. 



1. HIPPURIS L. Make's Tail. 



Stems erect, unbranrhed. Leaves simple, entire. Flowers minute, 

 usually perfect, sessile in the axils. Petals none. Calyx limb a nar- 

 row entire rim. Stamen 1, inserted on the anterior edge of the calyx. 

 Style 1, filiform, stigmatic down one side. Ovary 1-celled, becoming 

 a 1-seeded nutlet. (Greek hippos, a horse, and oura, a tail.) 



1. H. vulgaris L. Herbage glabrous; stem simple] to 2 ft. long 

 (commonly emersed 4 to 7 in.); leaves about 7 to 10 in a whorl, 

 linear, acute, I in. long; fruit nearly 1 line long. 



Shallow margins of ponds and about springs: Marin Co.; Sierra 

 Nevada. 



