CACTACE^E. (CACTUS FAMILY.) 109 



1. E. lobata, Torr. & Gray. Root annual : leaves deeply and sharply 

 5-lobed : fruit oval, 2 inches long: seeds flat, dark-colored. — Colorado and 

 eastward, in rich soil, to New York and Canada. 



Order 34. CACTACEJE. (Cactus Family.) 



Green fleshy and thickened persistent mostly leafless plants, of pecu- 

 liar aspect : globular or columnar, tuberculated or ribbed, or jointed and 

 often flattened, usually armed with bundles of spines from the areola. 

 Flowers with numerous sepals, petals, and stamens, usually in many 

 rows, the cohering bases of all of which coat the inferior one-celled 

 many-ovuled ovary, and above it form a tube or cup, nectariferous at 

 base. Style one, with several or numerous stigmas. Fruit a pulpy or 

 rarely dry one-celled berry. 



§ 1. No leaves proper : spines never barbed. Flower-bearing and spine-bearing areolae 

 distinct. Tube of the sessile solitary flowers well developed, often long. Seeds brown 

 or black, mostly small. — Cacte*:. 



1. Mamillaria. Globose or oval plants, covered with spine-bearing tubercles. Flowers 



from between the tubercles. Ovary naked. 



2. Echinocactus. Globose or oval plants, stouter than the last, usually ribbed : bundles 



of spines on the ribs. Flowers from the youngest part of the ribs close above the 

 nascent bunches of spines. Ovary covered with sepals. 



3. Cereus. Oval or columnar plants, sometimes tall, ribbed or angled : bundles of spines 



on the ribs. Flowers close above the bundles of full grown (older) spines. Ovary 

 covered with sepals. 

 § 2. Leaves small, subulate, early deciduous. Sessile and solitary flowers from the same 

 areolae as the always barbed spines. Tube of the flowers short, cup-shaped. Seeds 

 larger, whitish, covered with a bony arillus. — Opuntie^e. 



4. Opuntia. Branching or jointed plants : joints flattened or cylindrical. 



1. MAMILLARIA, Haw. 



Flowers about as long as wide : the tube campanulate or funnel-shaped. 

 Ovary citen hidden between the bases of the tubercles, the succulent berry 

 exsert. Seeds yellowish-brown to black. 



1 • M. vivipara, Haw. Simple or cespitose : the almost terete tubercles 

 bearing bundles of 5 to 8 reddish-brown spines, surrounded by 15 to 20 grayish 

 ones in a single series, all straight and very rigid : flowers purple, with lance- 

 sabulate petals and fringed sepals : berry oval, green : seed pitted, light brown. 

 — A variable species, ranging across the plains and along the eastern slopes 

 of the mountains. 



2. M. MiSSOUriensis, Sweet. Smaller, globose, simple, with fewer (10 

 to 20) iveaker ash-colored spines: flowers yellow : berries scarlet, subglobose : seeds 

 globose, pitted. — M. Nuttallii, Eng. Common along the eastern slopes of 

 the mountains and upon the plains. 



Var. caespitosa, Watson. Cespitose, with 12 to 15 straight white spines : 

 berry shorter than the tubercles, red. — Bibliog. Index, i. 403. M. Nuttallii, 

 var. cozspitosa, Eng Eastern, slopes of the mountains of Colorado and 

 southward 



