ELAEAGNACEAE (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 verticillate, horizontally 

 divaricate or pendulous, very spiny branches: joints verticillate (mostly in 

 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 8-30, terete, horny or reddish- 

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

 longer (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 cm. in 

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

 yellow: seeds regular, smooth, 3-4 mm. broad, with narrow commissure. 

 Colorado to New Mexico and Texas. 



11. Opuntia Davisii Engelm. & Bigel. Proc. Amer. Acad. 3: 305. 1856. 

 Stem 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 tubercles 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 ovate, spiny, 2.5cm. long or more. Texas, extending 

 north into Colorado. 



79. ELAEAGNACEAE Lindl. OLEASTER FAMILY 



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

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

 perfect 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 slender style, the solitary ovule becoming a 

 nut-like achene inclosed in the finally fleshy, drupe-like fruit (the perianth 

 base) . 



Flowers perfect; stamens 4; leaves alternate . . . . . .1. Elaeagnus. 



Flowers dioecious; stamens 8; leaves opposite 2. Shepherdia. 



1. ELAEAGNUS L. 



Shrubs with silvery-scaly alternate leaves and brownish or silvery branch- 

 lets. Perianth tubular, 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 with an 8-striate stone. 



1. Elaeagnus argentea Pursh, Fl. Am. Sept. 114. 1814. A stoloniferous 

 shrub 1-3 m. high, the younger branches brownish with scurfy scales, becom- 

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

 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. SILVERBERRY. Moist sandy swales and banks; from Utah through 

 Wyoming northward and eastward. 



2. SHEPHERDIA Nutt. 



Shrubs or small trees with opposite petioled leaves with silvery-stellate or 

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



