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 sjiiiies several; berry green, ellipsoid. 



Stems tufted. (leprt'.sso<l-j,'lobose; 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. Nolesteinii 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. M. 

 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 vivipar us '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 4-12, 

 tawny or pur])lish, 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 Engehn. Cactus radiosus Coulter. 

 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, polj^gamous or 

 dioecious. Hypanthium in the pistillate flowers tubular or urn-shaped, 

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

 Stamens 4 or 8. Disk present, annular or lobed. Ovary 1-celled, 1-ovuled. 

 Fruit drupe-like. 



stamens 4; flowers perfect or polygamous; leaves alternate. 1. EL.\EAGmJS. 



Stamens 8; flowers dioecious; leaves opposite. 2. Lepargyraea. 



1. ELAE AGNUS (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. Hypanthium tubular, 

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

 drupe-like. 



