Myriophyllum. HALORAGE.-E. 215 



small and short ; styles or sessile stigmas 2 to .4 and distinct, or in Hippuris only 

 one and simple. 



All the highly developed representatives of this small order are in the southern hemisphere 

 i it one in the Sandwich Islands) : such as we have are much more numerous in the Atlantic 

 than in the Pacific States. 

 Callitkkhe as well as Cekatophylll-ii is referred to the Apdalcc. 



1. Hippuris. Leaves linear, in whorls of 8 or 12. Flowers perfect. Calyx entire. Petals 



none. Stamen and cell of the ovary one. 



2. Myriophyllum. Immersed leaves pinnately dissected. Flowers monoecious or polygamous. 



Parts of the flower in fours. 



1. HIPPURIS, Linn. Make's Tail. 



Flowers perfect or sometimes polygamous. Calyx-tube globular ; the limb entire. 



Petals none. Stamen 1 ; filament subulate ; anther large. Ovary 1-celled : style 



becoming filiform and elongated, stigmatic the whole length. Fruit oblong-ovoid, 



nut-like. — Smooth aquatic perennial herbs, with erect simple leafy stems ; leaves 



linear or oblong, entire, in whorls of 4 to 12; flowers minute, solitary and sessile in 



the axils of the leaves. 



Only two species are known, or perhaps only one, distributed through the temperate and colder 

 regions of the northern hemisphere and also in the southern. 



1 . H. vulgaris, Linn. Stems a foot or two high, rather stout : leaves acute, 

 usually a half to an inch long but often much longer, especially the submerged 

 ones : calyx hardly half a line long: style and stamen comparatively conspicuous, 

 persistent : fruit nearly a line long. 



In shallow ponds ; Tomales Bay (Bigclow, Bolandcr) ; Soda Springs, near Mono Pass, at 8,600 

 feet altitude, Brewer, Bolander. Throughout the northern part of the continent (as well as of the 

 Old World), and southward in the Rocky Mountains as far as New Mexico. 



2. MYRIOPHYLLUM, Linn. Water-Milfoil. 



Flowers monoecious or polygamous. Limb of the calyx 4-lobed in the sterile 



flowers, wanting or minutely toothed in others. Petals 2 to 4, minute or wanting 



in pistillate flowers. Stamens 2 to 8 ; filaments filiform. Ovary t-celled: stigmas 



4, recurved and plumose. Fruit nutlike, deeply 4-lobed longitudinally. — Smooth 



aquatic perennial leafy herbs; leaves mostly verticillate or opposite, the submersed 



nues pinnately parted with capillary segments ; flowers small, solitary and mostly 



sessile in the axils of the reduced upper leaves, the upper ones usually staminate, 



the lower pistillate, and the intermediate ones perfect. 



A genus of aliout 15 species, distributed over nearly the whole globe, one half of the numKr 

 being found within tin- United States. 



1. M. spicatum, Linn. Leaves in whorls of 3 or I. all below the inflorescence 

 pinnately parted; tlie filiform segments often an inch long: dowers in an inter- 

 rupted spike; bracts ovate, entire or toothed, usually shorter than the Sowers: 

 petals ovate, greenish white, nearly a line long, deciduous: stamens 8: fruit sub- 

 globose, deeply lobcil ; the rounded carpels smooth, a line long. 



Collected in California I A' mi. but locality not given ; Washington Territon north- 



ward to Alaska and eastward across the continent. Also in Europe and Asia. The wry similar 

 J/, verticillatum, Linn., is distinguished bj the larger and pi pinnatifid floral 



-. M. hippurioides, Nutt. Leaves in whorls of I, the lower pinnate and 

 capillary; upper leaves linear, acute, acutely and rather remotely toothed, 3 to ."> 

 lines long, the uppermost nearly entire: petals white, obovate, somewhat persistent 



