CACTUS FAMILY. 581 



Flowers yellowish or greenish, merely tinged with red ; central spines 1 ; berry scarlet, 



globose. 



Stem usually simple or nearly so; central spines stout, porrect; flowers about 2.5 

 cm. long. 2. C. missouriensis. 



Stems tufted; central spine often wanting or small; flowers 3-4 cm. long. 



3. C. similis. 

 Flowers purple; central spines several; berry green, ellipsoid. 



Stems tufted, depressed-globose; central spines 3-4. 4. C. vivipara. 



Stems usually simple, ellipsoid or oblong; central spines 4-12, rarely 3. 



5. C. radiosa. 



1. C. Grahami (Engelm.) Rydb. Stem simple or clustered, globose, be- 

 coming ellipsoid, 3-8 cm. high; tubercles ovate, 6 mm. long; radial spines 15-30, 

 white, often dusky-tipped, 6-12 mm. long; central spines 1-3, blackish, with a 

 paler base, the lower one stouter and longer, 6-18 mm. long, hooked upwards; 

 flowers 2-2.5 cm. long, rose-colored; fruit 2-2.5 cm. long; seeds 1 mm. long, black. 

 M. Grahami Engelm. Rocky places: Tex. s Utah s Calif.; Sonora. L. Son. 



2. C. missouriensis (Sweet) Britton & Rose. Stem mostly simple, globose > 

 3-5 cm.; tubercles 12-15 mm. long, in about 8 spiral rows; spines gray, 10-20 

 together; central spine 10-12 mm. long; corolla greenish yellow or tinged with 

 reddish; berry globose, 6-8 mm. in diameter, ripening the next spring; seeds 

 black, 1 mm. long. M. missouriensis Sweet. M. Notesteinii Britton. Cactus 

 missouriensis Kuntze. Plains and hills: S.D. Mont. Colo. Kans. Plain. 

 My. 



3. C. similis (Engelm.) Britton & Rose. Stems clustered, forming masses 

 3 dm. broad; tubercles 1.5-2 cm. long, in 8 spiral rows; radial spines gray, 12 

 15, puberulent, the central one often lacking, not larger than the rest; corolla 

 yellowish, 3-5 cm. long; berry globose, 8-10 mm.; seeds 1.5-2 mm. long. 

 similis Engelm. Cactus missouriensis similis Coulter. Plains: Kans. Colo.- 

 Tex. Son. 



4. C. vivipara (Nutt.) Britton & Rose. Stems usually tufted, 3-5 cm. high; 

 tubercles terete, ellipsoid, slightly grooved; central spines 3-4, slender, reddish 

 brown, 8-12 mm. long, one of them deflexed, the others ascending; radial spines 

 12-20, white, often dark-tipped, 6-8 mm. long; flowers about 3.5 cm. long, bright 

 purple; fruit pale green, 12-18 mm. long; seeds yellowish brown, obliquely pear- 

 shaped, 1.5 mm. long. Cactus viviparus Nutt. M. vivipara Haw. Plains: Man. 



-Alta. Colo. Kans. Plain. 



5. C. radiosa (Engelm.) Rydb. Stems mostly simple, ellipsoid or cylindric, 

 5-12 cm. high and 5 cm. thick; tubercles 8-12 mm. long; central spines 4- 

 tawny or purplish, 8-12 mm. long, the upper the longer, the lowest small and 

 porrect; radial spines 20-30, white, 6-8 mm. long; flowers 3.5-5 cm. long, dark 

 purple; seeds 2 mm. long. M. radiosa Engelm. Cactus radiosus 

 Plains:' Kans. s Utah Sonora Tex. Son. 



FAMILY 89. ELAEAGNACEAE. OLEASTER FAMILY. 



Shrubs or trees, with silvery, scaly, or stellate pubescence. Leaves entire, 

 alternate or opposite. Flowers in axillary clusters, perfect, polygamous or 

 dioecious. Hypanthium in the pistillate flowers tubular or urn- 

 adnate to and enclosing the ovary. Sepals 4, deciduous. Corolla none 

 Stamens 4 or 8. Disk present, annular or lobed. 

 Fruit drupe-like. 



Stamens 4; flowers perfect or polygamous; leaves alternate. 1. ELAEAOM s 



Stamens 8; flowers dioecious; leaves opposite. 



1. ELAEAGNUS (Tourn.) L. SILVER-BERRY, SILVER-BUSH. 



Silvery-scaly shrubs or trees. Leaves alternate, petioled. Flowers soli- 

 tary or 2-4 together, axillary, perfect or polygamous, 

 constricted over the ovary. Sepals 4, deciduous, valvate. 

 drupe-like. 



