112.
Erigeron philadelphicus
Linnaeus, Sp. Pl. 2: 863. 1753.
Philadelphia fleabane, vergerette de Philadelphie
Annuals, biennials, or short-lived perennials,
4—80 cm; fibrous-rooted, caudices simple.
Stems
erect (green proximally, leafy to arrays), hirsuto-villous to villous proximally, loosely strigose to sparsely hirsute distally, minutely glandular.
Leaves
basal (persistent or withering by flowering) and cauline; basal blades oblanceolate to obovate, (15—)30—110(—150) × 10—25(—40) mm, margins shallowly crenate to coarsely serrate or pinnately lobed, faces sparsely hirsute to villous, eglandular; cauline blades oblong-oblanceolate to lanceolate, gradually reduced distally (bases clasping to auriculate-clasping).
Heads
(1—)3—35 usually in corymbiform arrays (ultimate branches arising near stem tips).
Involucres
4—6 × 6—15 mm.
Phyllaries
in 2—3 series (sometimes basally connate), hirsuto-villous to sparsely hirsute or glabrous, sometimes minutely glandular.
Ray florets
150—250(—400); corollas usually white, sometimes pinkish, 5—10 mm, laminae not coiling or tardily coiling.
Disc corollas
2.1—3.2 mm.
Cypselae
0.6—1.1 mm, 2-nerved, faces sparsely strigose;
pappi:
outer of setae, inner of 15—20(—30) bristles.
Varieties 3 (3 in the flora): North America, introduced worldwide in temperate areas as a weed.
