174 Mr. D. Don’s Descriptions of new Genera and Species 
ACHENIA nunc apice calva. 
Plante lactescentes. Folia alterna. Flores sæpiùs lutei. 
This family constitutes but a very small part of the Composite 
in the South American Flora, being scarcely in the proportion 
of one to forty-five, while in the European Flora they are gene- 
rally as one to two. The Cichoracee are readily distinguished 
from the other families of Composite by their uniform, ligulate, 
hermaphrodite florets. The primary vessels are five in the 
tube, but at the sinus, where the corolla splits open and expands 
into the ligulate lamina, the interior nerve divides into two 
simple branches, which run along the opposite sides, either 
directly on the margin itself, or more frequently placed a little 
within the border. The apparently simple trunks of the inter- 
mediate vessels divide a little below the sinus of the teeth, and 
traverse their margins, uniting at the summit of each tooth ; 
but I have only in one instance, that of Prenanthes virgata of 
Michaux, detected secondary vessels, and therefore conclude 
that they are rarely present in the plants of this family. The 
disposition of the vessels in the lamina of the corolla will be 
found an important character in distinguishing the Cichoracee 
from such individuals belonging to other families, whose florets 
may have assumed an analogous form. | 
. Besides being lactescent, the alternate leaves, their netvation, 
and the inequality of their teeth, when present, the irregularity 
of the corolla in Lobelia, the cohesion of its antherz, and its 
papillary stigmata, show that many analogies exist between this 
family and Campanulacee. 
Trib. 1. pHixnacrz. disce decidi epaleatum. Anthere basi 
ligula simplici iden brariabea truncatà aucte ! In- 
volucrum polyphyllum. ee | 
HIERACIUM. 
