2. M. Missouriénsis, Sweet. Smaller, globose, with fewer (10--20) weaker ash-colored spines; flowers yellow, 1--2´ broad; berry subglobose, scarlet; seeds few, black, pitted. (M. Nuttallii, _Engelm._)--S. Dak. to central Kan., Tex., and westward. 2. OPÚNTIA, Tourn. PRICKLY PEAR. INDIAN FIG. Sepals and petals not united into a prolonged tube, spreading, regular, the inner roundish. Berry often prickly. Seeds flat and margined, covered with a white bony arillus. Embryo coiled around albumen; cotyledons large, foliaceous in germination.--Stem composed of joints (flattened in ours), bearing very small awl-shaped and usually deciduous leaves arranged in a spiral order, with clusters of barbed bristles and often spines also in their axils. Flowers in our species yellow, opening in sunshine for more than one day. (A name of Theophrastus, originally belonging to some different plant.) [*] _Spines small or none; fruit pulpy._ 1. O. vulgàris, Mill. Prostrate or spreading, _light green_; joints broadly obovate (2--4´ long); _leaves minute_ (2--2½´´ long), ovate-subulate, _generally appressed_, bristles short, greenish yellow, rarely with a few small spines; flowers pale yellow (_about 2´ broad), with about 8 petals_; fruit 1´ long.--Sandy fields and dry rocks, Nantucket to S. C., near the coast; Falls of the Potomac. 2. O. Rafinésquii, Engelm. Prostrate, _deep green_; joints broadly obovate or orbicular (3--5´ long); _leaves_ (3--4´´ long), _spreading_; bristles bright red-brown, with a few small spines and a single strong one (9--12´´ long) or none; flowers yellow (_2½--3½´ broad), sometimes with a reddish centre; petals 10--12_; fruit 1½´ long, with an attenuated base.--Sterile soil, Nantucket and southward along the coast to Fla., and in the Mississippi valley, from Mich. to Minn., and south to Ky. and Ark. [*][*] _Very spiny, fruit dry and prickly._ 3. O. Missouriénsis, DC. Prostrate, _joints_ light green, _broadly obovate, flat and tuberculate_ (2--6´ long), leaves small (1½--2´´ long); _their axils armed with a tuft of straw-colored bristles and 5--10 slender radiating spines_ (1--2´ long); flowers light yellow (2--3´ broad), fruit with spines of variable length.--Wisc. to Mo., westward across the plains, very variable. 4. O. frágilis, Haw. Subdecumbent; _joints small_ (1--2´ long or less), _ovate, compressed or tumid, or even terete_; leaves hardly 1´´ long, red; _bristles few, larger spines 1--4, cruciate, with 4--6 smaller white radiating ones below_; flowers yellow.--Minn. to Iowa and Kan., and westward. ORDER 47. FICOÍDEÆ.