362 PLANTS FROM WHICH SENNA-LEAVES ARE OBTAINED. 
C. Senna of Linnaeus is the third species of which the 
Alexandrian leaves are composed, and, out of respect for 
the authority of old Linnaeus, by many ancient botanists 
considered as the prototype of the same. I can only con- 
sider it as the vehicle of all mistakes, which this name is 
intended to conceal. Most previous botanists have done 
the same (as Forskal did with ligustrina and lanceolata) 
when tired of further examination. I have found it identi- 
cal with C. obtusa, Roxburgh, obovata, Colladon, obtusata, 
etlpbovata, Hayne. The leaves of this species vary much 
in form ; all the more fully grown leaves are at the top 
broadly blunted {obtusata) and retuse (retusa) whilst the 
younger leaves present this characteristic less distinctly, 
and are more ovate (subovata, obovata.) In commerce, 
this species has been very correctly named from this latter 
character, and I shall therefore call it S. obovata. The 
climate in which the Senna obovata grows, imparts to the 
leaf its peculiar consistency. The color of the leaves is 
brownish-green ; those from Tripoli have a more delicate 
parenchyma than those from Saida and Aleppo ; those from 
Senegal are thicker and more like leather. The smell of 
these leaves is inconsiderable; their taste, when chewed, 
mucilaginous and herbaceous; the dark-green follicles, when 
ripe, have a contracted kidney-like form ; the unripe ones, 
however, have a more bottle-gourd, rounded form, and 
after the production of the seeds, which are somewhat 
torulose, have crest-like verticle protuberances projecting 
in the middle, and the seeds have very yellow-colored 
cotyledons. 
That Cynanchum Argel materially increases the smell 
of the Alexandrian leaves, and is, therefore, intentionally 
mixed with them, is now an established fact ; the pale-green 
leaves, whitish blossoms, and blackish fruit, of this plant, 
which are found among the so-called officinal leaves (as im- 
ported by us,) sufficiently mark their presence ; and in order 
to suppress entirely this adulteration, I propose to cease 
