76 EUPHORBIACE^E. Euphorbia. 



high, once to thrice trichotomous ; the upper nodes short : leaves oblong-ovate, acute, 

 4 to 6 lines long ; floral ones ternate, very broadly ovate, cuspidate : involucres 

 a line long, with truncate or emarginate or bind lobes ; glands stipitate, broadly 

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

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

 gelm. in Ives' Rep. 27. 



W. Arizona ; Kailroad Pass in the Cerbat Range (Newberry), and at Cottomvood Creek, 75 

 miles west of Prescott, Palmer. Some other perennial species of this group are found in Arizona 

 and may reach S. E. California: E. CAMPESTRIS, Cham. & Schlecht. (E. csulccformis, Schauer), 

 glabrous, with lanceolate acute leaves ; E. SUBPUBENS, Engelm., pubescent, with obtuse broadly 

 spatulate leaves ; etc. 



H Leaves opposite, linear to oblong-lanceolate, large. 



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

 high ; branches of inflorescence umbellate and twice or thrice dichotomous : 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. 



ORDER LXXXVIII. CALLITRICHACE^I. 



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, 

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

 in each cell ; fruit 4-lobed, flattened and emarginate, 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 (the number much 

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

 part of the globe. Five other species are credited to the Atlantic States. The affinities of the 

 order are various and its position disputed. It is often included among the Ilaloragcce, but on 

 the other hand has many characters of the Euphorbiaccce, from which it differs most strikingly in 

 the two styles and 4-celled indehiscent fruit. 



1. CALLITRICHE, Linn. WATER- STARWORT. 

 Characters as of the order. 



* Amphibious: floating leaves obovate-spatulate, S-nervetf, the submersed linear,' 

 all uniform and narrow in terrestrial forms : carpels connate. 



H Fruit 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 upper leaves : styles elongated, reflexed, 

 soon deciduous : mature fruit on slender spreading pedicels ( 1 to 4 lines long), deeply 

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

 widely divergent and narrowly winged. Pacif. R. Rep. iv. 135 ; Hegelmaier, Ver- 

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



