228 HALORAGE^. 



1. HIPPURIS, Linnxus. Erect stoiitish but low perennial aquatics. 

 Stem simple, short-jointed, with linear entire leaves in whorls of 8 or 12. 

 Calyx-tube globular ; the limb entire. Petals 0. Stamen 1 ; filament 

 subulate. Ovary 1-celled ; style becoming filiform and elongated, stig- 

 matic throughout. Fruit oblong-ovoid, nut-like, 1-seeded. 



1. H. vulgaris, Linn. Sp. PI. i. 4 (1753). Limnopeuce vulgaris, Vaill. 

 Mem. de TAcad. 15 (1719) ; Ray, Syn. Meth. 136 (1724). Stem if-1 ft. 

 high ; herbage glabrous : leaves J^ — 1 in. long, acute : calyx % line 

 long : style and stamen rather conspicuous : nutlet nearly 1 line long. — • 

 In shallow ponds and pools, and about springy places, from the seaboard 

 to the high Sierra ; but not often met with in California. 



2. MYRIOPHYLLUM, Matthiolus (Water-Milfoil). Aquatic per- 

 ennials. Leaves usually verticillate, sometimes opposite or alternate ; 

 the submersed ones pinnately divided into capillary or filiform segments; 

 the emersed ones pectinate or toothed or entire and bract-like. Flowers 

 axillary, commonly unisexual ; the staminate with a very short calyx- 

 tube, and 2 — 4-lobed limb or none. Petals 2 — 4. Stamens 4 — 8. Calyx 

 of pistillate fl. with a more or less deeply 4-grooved tube and 4 minute 

 lobes or none. Styles 4, short, often plumose and recurved. Fruit 

 somewhat drupaceous, quadrangular, when ripe splitting into 4 one- 

 seeded carpels. 



1. M. spicatum, Linn. Sp. PI. ii. 992 (1763). Stems often many feet 

 long, growing in deep waters, branching above : flowers in emersed 

 short-peduncled verticillate spikes 2 — 3 in. long ; bracts reduced and 

 inconspicuous ; submersed leaves in whorls of 4 or 5 : petals 4, deciduous : 

 stamens 8 : carpels rounded on the back, with a deep wide groove between 

 them. — Perhaps not rare in California, but known only in Mountain 

 Lake, San Francisco, where it is abundant and of rank growth in two or 

 three feet of water. July. 



2. M. hippuroides, Nutt.; T. & G. Fl. i. 530 (1840); Morong, Bull. 

 Torr. Club, xviii. 245. Stems 4 — 8 in. long, growing in mud or shallow 

 water, the emersed branches erect, simple, leafy, flowering throughout 

 their length : submersed leaves in whorls of 4 and 6, with 6 — 8 pairs of 

 capillary pinnae ; emersed ones often alternate, linear-lanceolate, serrate 

 or dentate, or the uppermost entire ; the lowest often pinnatifid : petals 

 often pinkish and somewhat persistent : stamens 4 : carpels carinate and 

 somewhat roughened ; deep grooves between them. — Rather common in 

 Lake and Marin counties ; also at Stockton. June. 



3. CALLITRICHE, Columaa. Small and slender, growing in water 

 or on moist shaded ground. Leaves opposite, linear, spatulate or obovate. 

 Flowers solitary in the axils, subtended by a pair of falcate or lunate 

 membranous bracts, mostly consisting of a single stamen and pistil. 



