Part 83 (1/2)

95. Pyrrhopappus. Scapose or branched. Pappus reddish, the base surrounded by a soft villous ring.

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-gla.s.s to make them out, and will not always be clear to the student. The following artificial a.n.a.lysis, founded upon other and more obvious distinctions, will be useful to the beginner.

Artificial Key to the Genera of the Tubuliflorae.

-- 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

Simple, the bristles all of the same sort.

Heads few-flowered, themselves aggregated into a compound or dense cl.u.s.ter 1

Heads separate, few-flowered or many-flowered.

Receptacle (when the flowers are pulled off) bristly-hairy 78, 79, 80

Receptacle deeply honeycomb-like 81

Receptacle naked.

Pappus of plumose or bearded stiff bristles. Flowers purple 8

Pappus of very plumose bristles. Flowers whitish 6

Pappus of slender but rather stiff rough bristles 4, 5, 7, 9, 16

Pappus of very soft and weak naked bristles 76, 77

Pappus composed of scales or chaff.

Receptacle naked. Leaves in whorls 3

Receptacle naked. Leaves alternate, dissected 61

Receptacle bearing chaff among the flowers 59, 64

Pappus of 2 or few awns or teeth 53, 57, barbed in 55, 56