ELABAGJSTACEAE (OLEASTER FAMILY) 331 



bilicus, 2.5-3 cm. long: seeds large (6 mm. broad), much compressed, with 

 broad, acute margins. — Southwestern Wyoming to Nevada. , 



10. Opuntia arborescens Engelm. Wisliz. Mem. 90. 1848. Arborescent and 

 erect,. 15-50 dm. high,, 12.5-25 cm. in diameter, with vertioillate, horizontally 

 divaricate or pendulous, very spiny branches: joints verticiUate (mostly ,m 

 threes or fours), cylindrical and very green, 5-15 cm. long, less than 2.5 cm. 

 in diameter, with prominent, elongated, compressed-cristate tubercles 14-18 

 mm. long; and terete, elongated, spreading leaves 12-20 mm. long: pulvini 

 with short wool, but scarcely bristly;. spines 8-3p, terete, horny or reddish- 

 brown, in straw-colored sheaths, porrect in 'every direction, 1-8' interior ones 

 loiiger (16-28 mm.), more loosely sheathed, the central subdeflexed, the ex- 

 terior ones weaker, closely sheathed, 8-16 mm. long, all sometimes Very short: 

 flower -purple, 6-7.5 cm. broad: fruit globose or hemispherical,' 2.5 elm. in 

 diameter, prdibinelitly cristate-tuberculate, unarmed, dry or nearly so, 

 yellow: seeds regular, smooth, 3—4 mm. blroad,' ivith narrow commissure. — ■ 

 Colorado to. New Mtexico and Texas;' ' I'l - 



11. Opuitia Davisii Engelm. & Bigel. Proo. Amer. Acad. 3: 305. 1856. 

 Stein, spreading and somewhat, procumbent, with dense woody and divaricate 

 branches, 4-5 dm. high: joints attenuate at base, rather slender, 10-15 cm. 

 long (younger ones erect), with oblong-linear iubercles 14-16 mm. long: inner 

 spines 4-7, subtriangular, divergent, reddish-brown, in a loose straw-colored 

 sheath, 2.5-3.5 cm. long; lower ones 5 or 6, slender, 6-12 mm. long: flower 

 yellowish (?): fruit q^vajie, j spiny, 2.5 cni. jlong or'more. — ^Texas, ; jExtending 

 north into Colorado. 



19. ELAEAGNACEAE Lindl. Oleaster Family 



Shrubs or small tirees with the entire leaves scurfy throughout,- with scarious- 

 silvery or brown scales or with silvery stellate-pubescence. Flowers regular, 

 perfggt or dioecious, clustered in the axils or solitary. Perianth of fertile 

 floWers with a deciduous 4-lobed limb and a persistent base inclosing the 

 ovary. Perianth of sterile flowers 4-parted, bearing the 4 or 8 stamens on 

 the throat. Pistil simple, with slehder style, the solitary ovule becoming a 

 nutrlik^. aohene inclose4 m the finally fleshy, drupe-like ,fruit (the perianth 



Flowers perfect; stamens 4; lekves alternate . ' . . . ' . . 1. Elaeag&us. 

 Flowers dioecious; stamens 8! leaves opposite . . . ' . .' . .2v Shepherdia. 



1. ELAEAGNUS L 



•;,. Shrubs, with silwery-scaly alternate !leaves and, broypish or silvery branch- 

 lets. Perianth tubiilar, its 4-lobed limb deciduous, its tube contracted .over 

 the ovary. Stamens 4, borne on the throat of the perianth and alternate 

 with its lobes. Fruit drupe-like, withan Srstriate ^tone. 



1.' Elaeagrjus a|;gentea Pursh, Fl. Am, Sept. 114. 1814. A. stoloniferous 

 shrub 1,73 m, tiigh, the younger bralhches bfownisl^ with scurfy Scales, becom- 

 ,ing silvery:, leaves from broadly to narrowly elliptic, silvery-scurfy: flbwers 

 numerous, 12-15 mm,, long, 1-3 in the axils, deflexed, silVery without, pale 

 yellow within, fragrant, the lobes ovate: fruit globose-ovoid, silvery, 8-10 mm. 

 long. SiLVERBEBRY. — Moist Sandy swales and banks; from Utah through 

 Wyoming northward and eastward. - ' •, , , ,, 



2. SHEPHERDIA Nutt. 



Shrubs or small trees with opposite petioled. lea,ves with silvery-stellate or 

 scurfy-brownish scales. Flowers Small, dioecious, axillary or nodal,, fascicled, 



