Mamittaria. CACTACE^E. 243 



in many series, the cohering bases of all of which coat the inferior 1 -celled many- 

 ovuled ovary, and above it form a tube or cup, nectariferous at base. Style 1, 

 with several or numerous stigmas. Fruit a pulpy or rarely dry 1-celled berry, 

 with numerous campylotropous seeds (without or with some albumen) on several 

 parietal placentae. 



An order of few genera, comprising a large number of species, peculiar to the warmer parts of 

 America, and confined in California to the southern and southeastern districts. 



SUBORDER I. CACTEvE. 



No leaves proper : spines never barbed. Flower-bearing and spine-bearing areolas 

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

 brown or black, mostly small. The limits between the genera are arbitrary. 



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



small) from between the tubercles. Ovary naked. Seeds without albumen. 



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



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

 the nascent bunches of spines. Ovary covered with sepals. Seeds albuminous. 



3. Cereus. Oval or columnar plants, sometimes tall, ribbed or angled ; bundles of spines on the 



ribs. Flowers usually larger, close above bundles of full grown (older) spines. Ovary 

 covered with sepals. Seeds without albumen. 



SUBORDER II. OPUNTIE^E. 



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. 



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



SUBORDER III. PEIRESCIE^E, with flat persistent leaves, spines never barbed, flowers 

 usually peduncled and often paniculate, with a very short tube, and large black albuminous seeds, 

 includes the genus Pcirescia of the tropics, in aspect very unlike the rest of the order. No species 

 have been found in California, but they may be expected in the Peninsula. 



1. MAMILLARIA, Haworth. 



Flowers about as long as wide ; the tube campanulate or funnel-shaped. Ovary, 

 often hidden between the bases of the tubercles, as well as the exsert succulent 

 berry, naked. Seeds yellowish-brown to black, exalbuminous or nearly so. Embryo 

 mostly short and straight, with extremely short cotyledons parallel to the sides of 

 the seed. Small more or less globose or oval simple or cespitose plants, the spine- 

 bearing areolse borne on cyliudric, oval, conic, or angular tubercles, which cover the 

 body of the plant. Flowers from a distinct woolly or bristly areola at the base 

 of these tubercles, fully open in sunlight, mostly only for a few hours. 



1. Flowers usually small, lateral from the axils of older or full-grown tubercles. 

 Our species have limpid juice and exsert ovaries, EUMAMILLARIA. 



1. M. Groodridgii, Scheer. Oval to subcylindrical, mostly single, covered with 

 crowded ovate tubercles and a dense mass of gray and dusky thin spines ; axils of 

 the younger tubercles woolly and bristly : the 10 to 15 outer spines radiating and 

 whitish ; the 1 to 3 inner ones longer, stouter and dark brown, of which the stout- 

 est is strongly hooked : lower sepals fringed : petals about 8, ovate, awned : stigmas 

 5 to 6 : club-shaped berry scarlet : seeds obovate, minute, black, delicately pitted. 

 Salm. Cact. 1849, 91 ; Engelm. Cact. Mex. Bound. 8, t. 8, fig. 9-14. 



