96. Chondrilla. Stem branching, leafy. Involucre few-flowered, calyculate. Pappus white.
[+][+] Achenes flat or flattish. Pappus white, fine and soft. Involucre imbricated. Leafy-stemmed, with panicled heads.
97. Lactuca. Achenes more or less beaked. Flowers yellow or purplish.
98. Sonchus. Achenes flattish, not at all beaked. Flowers yellow.
The technical characters of the tribes, taken from the styles, require a magnifying-glass to make them out, and will not always be clear to the student. The following artificial analysis, founded upon other and more obvious distinctions, will be useful to the beginner.
Artificial Key to the Genera of the Tubulifloræ.
§ 1. Rays or ligulate flowers none; corollas all tubular (or rarely none).
[*] 1. Flowers of the head all perfect and alike.
Pappus composed of bristles:
Double, the outer of very short, the inner of longer bristles No. 2