>jQ EUPHORBIACE.E. Euphorbia. 



high, once to thrice trichotomous ; tlie upper nodes sliort : leaves oblung-ovate, acute, 

 4 to 6 Unes long ; floral ones ternate, very hroadly ovate, cuspidate : involucres 

 a line long, with truncate or eniarginate or bilid lobes; glands stipitate, broadly 

 dilated, crenate or irregularly indented : styles elongated (much longer than the 

 ovary), united at base. — Proc, Am. Acad. v. 173; Uoiss. 1. c. 148. E. incisa, En- 

 gelra. in Ives' Kep. 27. 



W. Arizona ; Raihoad Pass in the Cerbat Range {Neichcrry), and at Cottonwood Creek, 75 

 miles west of Prescott, I'almcr. Some other jierennial species of this group are found in Arizona 

 and may reacli S. E. California: — E. campestiu.s, Cham, k Scbleclit. (£. csulaformis, Schauer), 

 glabrous, witii lanceolate acute leaves ; E. suupubens, Engcha., pubescent, witU oljtuse broadly 

 spatulate leaves ; etc. 



-K- -1- Leaves ojiposlte, linear to ohloiKj-lanceolate, lanje. 



14. E. LathyriS, Linn. Annual or biennial, glabrous, erect, stout, 1 to 3 feet 

 hi"h ; branches ot inlloroscence umbellate and twice or thrice dichotoujous : leaves 

 sessile, obtuse and cuspidate, 3 or 4 inches long, the lower linear, the upper oblong- 

 lanceolate, cordate at base ; the floral oblong-ovate : glands crescent-shaped, with 

 broad obtuse horns : capsule 4 lines in diameter, with rounded lobes, smooth becom- 

 ing wrinkled : seeds reticulate-rugose, carunculate. 



Naturalized about Monterey and San Buenaventura ; a native of S. Europe and W. Asia, now 

 very widely distributed. 



OuDEii LXXXVIII. CALLITRICHACE^. 



Small slender herbs, mostly aquatic, with opposite entire leaves, no stipules, and 

 monoecious axillary flowers without perianth, but often with 2 membranous bracts ; 

 stamen 1, with slender filament and heart-shaped 4-celled anther; ovary 4-celled, 

 Avith 2 filiform papillose styles, mostly deciduous, and a pendulous anatropous ovule 

 in each cell ; fruit 4-lobed, flattened and eraarginate, 4-seeded, indehiscent ; embryo 

 slender, in the axis of oily albumen, the cotyledons very short and radicle superior. 

 Flowers mostly solitary, sometimes a male and female in the same axil. Cells of 

 the fruit separating at maturity. 



A single genus of 15 to 20 or more rather obscurely defined species (tlie number much 

 reduced by some authors), found mostly in still waters or sometimes tenestrial, in almost every 

 part of the globe. Five other species are credited to the Athmtic States. Tlie alhiuties of tho 

 order are various and its jiosition disputed. It is often included among the Ifaloraf/cce, but on 

 the other hand lias many characters of the Euphorhiucccc, from which it dilfers most strikingly in 

 the two styles and 4-celied indehiscent fruit. 



1. CALLITRICHE, Linn. WATKii-SrAUWoiiT. 

 Characters as of the order. 



* Amphihimis : floating leaves ohnvate-spatuhite, S-nervcl, the submersed linear; 



all uniform and narrow in terrestrial forms : carpels connate. 



H- Fniit pedicellate, wing-margined : bracts none. 



1. C. marginata, Torr. Often small and rooting in the mud, with linear or 

 linear-oblanceolate leaves 2 or 3 lines long or less, or sometimes floating with very 

 slender stems and rather broadly spatulate u[)per leaves : stylos elongated, reflexed, 

 soon deciduous : mature fruit on slender spreading i)e(licels(l to 4 lines long), deeply 

 emarginate above and below, broader than high, the margins of the thick carpels 

 widefy divergent and narrowly winged. — Pacif li. Rep. iv. 135; Uegelmaier, Ver- 

 handl. Bot. Verein. Lrandenb. ix. 12, fig. 19-23, and x. 102. 



