934 CONTRIBUTIONS FROM THE NATIONAL, HERBARIUM. 



ments white, lanceolate, acute, spreading; filaments much shorter than the 

 inner perianth segments, purple ; stigma lobes about 7, long, twisted ; ovary 

 naked except at top, small ; fruit 7 mm. long ; seeds 3 mm. in diameter. 



31. LEUCHTENBERGIA Hook, in Curtis's Bot. Mag. 74: pi. J,393. 1848. 



A single species is known. 

 1. Leuchtenbergia principis Hook, in Curtis's Bot. Mag. 74: pi. 4393. 1848. 



Central and northern Mexico ; type from Real del Monte, Hidalgo. 



Plants up to 50 cm. high, 5 to 7 cm. in diameter, with a large or branched 

 tap-root, often 12 cm. long ; txibercles erect, ascending or widely spreading, 

 very woolly in their axils, bluish green, 10 to 12.5 cm. long, more or less 3- 

 angled, nearly truncate at apex, gradually dying off below and leaving broad 

 scars on the trunk ; spines papery, thin ; radial spines 8 to 14, about 5 cm. 

 long ; central spines 1 or 2, sometimes 10 cm. long ; flowers lasting for several 

 ■days, fragrant, solitary, from just below the tips of the young tubercles, more 

 or less funnelform, the limb when widely expanded 10 cm. broad ; outer peri- 

 anth segments reddish with a brown stripe down the middle ; inner perianth 

 segments oblong, acute, serrate at apex ; stamens and style somewhat exserted ; 

 stigma lobes 9 to 12, linear ; fruit probably dry ; seeds dark brown, minutely 

 tuberculate. 



The plants are said to be employed as a remedy for wounds in beasts of 

 burden. 



32. ECHINOFOSSULOCACTUS Lawrence; Loud. Gard. Mag. 17: 317. 1841. 



Mostly rather small plants, rarely over 10 cm. in diameter, but generally 

 much smaller, usually solitary, rarely clustered, deep-seated in the ground, 

 globular or depressed, or very old plants becoming short-cylindric ; ribs usu- 

 ally numerous, in one species as few as 10, in other 50 to 100, usually very 

 thin, more or less wavy; areoles on each rib sometimes only 1 or 2, always 

 felted when young ; spines in numerous clusters often covering the plant, some 

 of them strongly flattened and ribbon-like ; flowers small, campanulate to sub- 

 rotate with a very short tube; stamens numerous, shorter than the perianth 

 segments ; scales on the perianth and ovary few to numerous, scarious, naked 

 in their axils ; fruit globular to short-oblong, bearing a few papery scales, 

 these perhaps deciduous in age ; seeds black with a broad basal truncate hilum. 



All the species of the genus are natives of Mexico. 

 Ribs thick at base, triangular in cross-section. 



Ribs 10 to 14 1. E. coptonogonus. 



Ribs about 35 3. E. hastatus. 



Ribs always numerous, very thin, even at base. 



Ribs 100 or more 3. E. multicostatus. 



Ribs 25 to 55. 



Radial spines all or partly acicular. 



Upper radial spines, like the others, acicular, white, straight. 

 Flowers greenish yellow. 



Central spines terete 4. E. wippermannii. 



Central spines narrow but flattened 5. E. heteracantlius. 



Flowers not greenish yellow. 



Central spines 4 6. E. albatus. 



Central spines 3. 



Central spines annulate ; apex of plant not depressed. 



7. E. lloydii. 

 Central spines not annulate; apex of plant umbilicate. 



8. E. zacatecasensis. 



