278 FLORA OP TEXAS. 



with a single pointed stigma. Lower Kio Grande. Dr. J. 

 Gregg described it in 1848. 



0. STiiiGiL. Stems 2° high, pale green; joints covered 

 with numerous pulvilli, each with a bunch of bright red- 

 brown spines, paler at the tip, which gives the plant a very 

 shoAvy appearance; joints 4' or 5' long, 3-4' wide; spi7ies 

 5-8; floiver not described; fruit 6"-7" long and about 6" 

 thick. Around San Antonio. 



0. Engelmannii. a stout coarse-looking plant, 4°-6° 

 high ; lower part of the old ste7ns woody, with loosely 

 reticulated ligneous fibers, and with a gray back often 

 covered with lichens about 6' in diameter; joints in larger 

 species 1° \ong ; Jloivers 2-3' in diameter; ovar?j short; 

 petals compai-atively narrow and not emarginate. Ovary 

 H' long \ fruit sub-globose, dirty purplish; pulp bright 

 purple ; insipid and even nauseous taste. New Braunfels. 

 — Dr. Lin dimmer. 



0. MACRORHiZA. Roots large, tuberous; ^owe?'-bud 

 long-acuminate, and the stigmata always 5. Austin and 

 San Antonio. — Dr. Lindheimer. 



MAMMILARIA. 



Tube of the calyx adherent to the ovary ; the lobes 5-6, 

 crowning the young fruit, colored; petals 5-6, scarcely 

 distinct from the calyx, longer than the sepals and united 

 Avith them into a tube; stamens filiform, in several series; 

 styles filiform ; stigma 5-7-cleft, radiate ; herry smooth. 

 Plant roundish or somewhat cylindrical, destitute of a 

 woody axis, often with a somewhat milky juice, covered 

 Avith conical or mammaeform croAvded spirally-disposed 

 tubercles, Avhich bear deciduous spines and tomentum at 

 their extremity ;/?o/6'er.s sessile among the tubercles, usually 

 in a transverse zone. — De Candolle. 



