VOL. II.] 



CACTUS FAMILY. 



465 



7. Opuntia arborescens Engelm. North- 

 ern Tree-like Cactus. (Fig. 2533.) 



Opuntia arborescens Engelm. Wisliz. Rep. 6. 1848. 



Erect, tree-like, 4-25 high, 4'-%' in diameter at 

 the base, verticillately branched, the spiny branches 

 spreading or drooping. Joints verticillate, mostly 

 in 3's or 4's, cylindric, 2 / -6 / long, less than i' in di- 

 ameter, the prominent tubercles 7 // -io // long; leaves 

 terete, spreading, 6 // -io // long; spines 8-30, terete, 

 in yellowish sheaths, diverging, the interior ones the 

 longer, often i' long or more; flowers purple, 2^'- 

 3' broad; fruit subglobose, crested-tuberculate, dry, 

 or nearly so, yellow, unarmed, about i' in diameter; 

 seeds smooth, i^ // -2 // wide. 



Western Kansas (according to B. B. Smyth), Colo- 

 rado to Texas, New Mexico and Mexico. 



Family 83. THYMELEACEAE Reichenb. Consp. 82. 1828. 



MEZEREON FAMILY. 



Shrubs or trees (rarely herbaceous), with tough fibrous or reticulated inner 

 bark, and simple entire exstipulate leaves. Flowers fascicled, capitate, racemose, 

 or rarely solitary, regular, mostly perfect. Calyx inferior, its tube cylindric 

 or urn-shaped, 4-5-lobed or entire. Petals none in our genera, present in many 

 exotic ones. Stamens borne on the calyx, twice as many as its lobes, or rarely 

 fewer, often in two series; filaments long or short; anthers erect, 2-celled, the 

 sacs longitudinally dehiscent. Ovary i-celled, i-ovuled (2-celled and 2-ovuled 

 in some Asiatic and Australasian genera) ; ovule anatropous, pendulous; style 

 short or elongated; stigma terminal, mostly capitate. Fruit a berry-like drupe 

 in our plants. Seed-coat mostly crustaceous; embryo straight; cotyledons 

 fleshy; endosperm little or none, or copious in some exotic genera. 



About 37 genera and 425 species, widely distributed, most abundant in Australia and South Africa. 

 Calyx-lobes 4, large; stamens included; style very short. I. Daphne. 



Calyx-limb almost wanting; stamens and style long, exserted. 2. Dirca. 



i. DAPHNE L. Sp. PI. 356. 1753. 



Erect or spreading shrubs, with alternate deciduous or evergreen leaves, and small pur- 

 ple pink or white flowers in fascicles, heads or racemes, borne in the following species at the 

 leafless nodes of twigs of the preceding season. Perianth tubular, its 4 lobes spreading. 

 Stamens 8, in 2 series on the perianth-tube, included, or the upper 4 slightly exserted; fila- 

 ments very short. Disk none. Ovary sessile or nearly so, i -celled; style very short; stigma 

 large, capitate. Drupe ovoid, or oblong, the calyx deciduous or persistent. 



About 40 species, natives of Europe and Asia. 



i. Daphne Mezereum L. Spurge Laurel. 



Lady Laurel. Mezereon. (Fig. 2534.) 

 Daphne Mezereum I,. Sp. PI. 356. 1753. 



A shrub i-4 high, the young twigs somewhat 

 pubescent. Leaves thin, deciduous, oblong-lanceolate 

 or oblanceolate, acute or obtusish at the apex, $'-$' 

 long, 4 // -io // wide, narrowed into short petioles; 

 flowers in sessile fascicles of 2-5 at the nodes of twigs 

 of the preceding season, very fragrant; perianth-tube 

 appressed-pubescent, rose-purple or white, 6" long or 

 less, the ovate acute lobes nearly as long; drupe red, 

 oval-ovoid, $"-4" long. 



Escaped from cultivation, Quebec to Massachusetts and 

 New York. Native of Europe and Asia. Called also 

 Spurge Olive, Dwarf Bay, Paradise Plant. April-May. 



30 



