2&Q ICOSANDUIA MONOGTXIA. 



plant becomes dry, excessively spiny, and almost juice- 

 less, in the spring numerous shoots issue from the root, 

 and those glomeruli which have withstood the intensity of 

 the frost, thus the plants becomes cespitose, forming 

 masses sometimes of 2 or 3 feet in breadth. In spite of 

 its armature the wild antelope of the plains finds means to 

 render it subservient to its wants by cutting it up with 

 his hooves. 



The flowers are generally central, more than an iwch in 

 length; segments of the calix linear, exterior ones revo- 

 lute with a fringed margin; petals numerous, narrow, li- 

 near and acuminate; berry about the size of grape, smooth 

 and eatable; seed small, cotyledones none, (in the seeds 

 which germinated with me, 'merely a tubercle similar to 

 those of the parent plant.) 



ff Opunti>e. Compressed, articulations proliferous. 

 Seeds larger, with 2 distinct cotyledones] 



3. Opiintia. (Common Indian Fig, or Prickly-Pear.) Ar- 

 ticulations compressed, ovate; spines double, exterior 

 ones strong and subulate, often deciduous, interior seta- 

 ceous; fruit succulent, smooth. Had. Common in sandy 

 fields from New Jersey to Florida. — Cotyledones 2, rolled 

 hori^^ont ally around the radicle, which is directed towards 

 the umbilicus. 



4. *Jerox. Articulately proliferous; articulations larger, 

 nearly circular and very spiny; spines double, larger 

 spines radiate persistent; flowers numerous; fruit dry and 

 spiny. Hab. In arid situations on the plains of the Mis- 

 souri, common. Ous. A much larger plant than C. opuu' 

 tia to which it is nearly allied; exterior spines radiate, 

 with one of them central, solitary and erect; flowers ag- 

 gregated, marginal, dilute sulphur yellow, rosaceous to- 

 wards the base; petals subemarginate. Style tiiick, stig- 

 mas 8 to 10 greenish. Colytedones 2, distinct. Flowering 

 in July. Upon this species I found the Coccus coccinelU- 



Jems. 



5. * fragilis. Articulately proliferous; articulations 

 short and oblong, somewhat terete, doubly spiny and fra- 

 gile; flowers solitary, small, at the point of the articula- 

 tions; fruit dry and spiny. Hab. From the Mandans to 

 the mountains, in sterile, but moist situations, much 

 smaller than the preceding, and remarkable for its brit- 

 tleness, the articulations though not very tumid com- 

 ing off" and attaching themselves to every thing which 

 they happen to touch, so much so as to lead the hunters 

 to say that it grows without roots. — Most of the species 

 of this section have irritable or sensitive stamina. 



An American genus of near 40 species, almost exclu' 



