CALLITEICHACEAE ( WATER STARWORT FAMILY) 311 



petioled leaves: involucres in terminal clusters, oblong-campanulate, about 

 3 mm. longj :3-5-lobed, with 1-4 short-pediceled glands without appendages: 

 capsules glabrous: seeds ovoid or subglobose, slightly tuberculate. — Extend- 

 ing into Colorado from the east. 



11. Euphorbia Aliceae A. Nels. Bot. Gaz. 42: 60. 1906. Perennial from 

 slender horizontal rootstocks, glabrous or slightly pubescent, 10-15 cm,, high: 

 stem branching from the base, the branches spreading-decumbent: leaves 

 narrowlyoblanceolate, short-petioled, sharply serrate, opposite, more crowded 

 toward the terminal clustered involucres: involucres nearly sessile, small, 

 turbinate, somewhat fimbriate-margined; the glands about 4, small, short- 

 stipitate, sometimes minutely cornuate or even obscurely appendaged: cap- 

 sules glabrous: seeds cubical, with a caruncle, sUghtly tuberculate, ashy. — 

 iKnown as yet only from Hartville, Wyoming. 



12. Euphorbia ctiphosperma (Engehn.) Boiss. in DC. Prodr. 15^: 73. 1862. 

 Annual, sparingly rough-pubescent: stem simple or somewhat branched up- 

 ward with erect slender branchlets, 2-5 dm. high: leaves opposite or alter- 

 nate, narrowly linear-lanceolate, acute, subentire: involucres 3-5, corymbose, 

 subsessile, cainpanulate, with ovate lobes; glands 4, long-stipitate, imappen- 

 daged: seeds irregularly 4-angled and slightly tuberculate. — From Dakota 

 to Mexico. 



13. Euphorbia robusta (Engelm.) Small, in Brit. Fl. 2: 381. 1897. Gla- 

 brous: stems shOjrt, stout, tufted on the crown of a perpendicular rootstock, 

 1-2 dm._ high: leaves scattered, oblong-ovate, 10-14 mm. long, entire, obtuse, 

 sessile: involucres terminal in a 3-5-rayed imibel, campanulate, bearing 4 

 imappendaged crescent-shaped glands: capsule of 3 ovate rounded lobes: seeds 

 terete, gray, minutely pitted. E. montana in part. — Montana to Colorado. 



14. Euphorbia montana Engelm. Bot. Mex. Bound. Surv. 192. 1859. 

 Resembling the preceding but the stems few, slender and taller, somewhat 



■ branched below the umbel: usually somewhat pubescent on the involucre and 

 the floral leaves: glands short-stipitate and bearing 2 short hom-hke pro- 

 tuberances: seeds ovoid-oblong, asn-colored, deeply and irregularly pitted. — 

 Southern Colorado and to the southwest ward. 



i5, Euphorbia arkansana Engelm. & Gray, Bost. Joum. Nat. Hist. 5: 53. 

 1845. Annual, glabrous, erect, branching above, 2-5 dm. high: stem leaves 

 few, cuneate-spatulate or oblanceolate, 1-5 cm. long; upper leaves oblong to 

 triahgular4ovate: involucre small, its lobes short; glands, yellow, transversely 

 lelliptical: capsule depressed-globose, more or less warty: seeds ovoid-lentipular, 

 with sharp reticulations. E.dictyosperma. Quite variable. Several varieties 

 have been characterized by J. B. S. Norton in the Eleventh Rep. Mo. Bot. 

 Gard. — ^From Wyoming to Mexico. 



16. Euphorbiamanca A. Nels. 1. c. 47: 437. 1909. Annual, the decumbent 

 base giving rise to few-several simple erect branches 1-2 dm. high: leaves 

 obovate-cunea.te, broadly obtuse, numerous, lower reduced;, primary floral 

 bracts ovate-reniform; secondary broadly reniform, sometimes coiinate: in- 

 florescence once or twice trichotomous: capsule about 4 mm. long: seeds short, 

 cyUndrical-oblong, gray but not ashy,, hearly smooth. — Colorado. 



17. Euphorbia commutata Engelm. in dray Man. Ed. 2. 389. 1856. Bien- 

 nial, branched from the base, glabrous, 1-3 dm. high: leaves scattered, thin 

 and membranaceous, petioled, round-obovate or the upper ovate: umbels 

 terminal, 3-rayed and again forking or 3-rayed: involucres campanulate, 

 sessile; glands 3-4, unappendaged, prolonged into slender horns: capsule 

 obtusely angled, glabrous: seeds terete, irregularly pitted. — Extending into 

 our range from the eastward. 



65. CALLITRICHACEAE Lindl; Water Starwort Family 



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

 monoecious, axillary flowers without perianth, but sometimes with 2 bracts. 

 Stamen 1, with slender filament and heart-shaped 4-celled anther. Ovary 



