Annuals (biennials, or perennials)
[shrubs, subshrubs], (5-)20-120 cm (sometimes rhizomatous). Leaves
basal and/or cauline (mostly cauline at flowering), alternate; usually sessile; blade margins entire or ± dentate to serrate. Heads
radiate [disciform or discoid], in corymbiform, racemiform, or paniculiform arrays. Involucres
hemispheric to campanulate, [3-]5-10[-20+] mm diam. Phyllaries
persistent (reflexed in fruit), in (2-)3-4+ series, unequal to subequal. Receptacles
flat, smooth or minutely alveolate, epaleate. Ray florets
(10-)20-30[-60+], pistillate, fertile; corollas yellow, laminae 1.5-2+ mm. Disc florets
(9-)40-100[-150+]; corollas yellow, lobes 5. Cypselae
ellipsoid (abruptly constricted distally; often glandular distally); pappi
persistent, outer of basally connate, ± erose scales (usually forming cups), inner of distinct (fragile), barbellate or flattened bristles. x
= 7, 9, 10. Pulicaria arabica
(Linnaeus) Cassini (Vicoa auriculata
Cassini) was collected in Alabama, California, and Florida in the late 1800s. It does not appear to have become naturalized at any of those locations (A. Cronquist 1980; J. E. Arriagada 1998).
Pulicaria dysenterica (Linnaeus) Bernhardi was collected in the late 1800s as a ballast weed in New Jersey and in Pennsylvania. It was collected in the 1920s growing on the margins of a marsh in Maryland. Although it is widely cultivated for its insecticidal properties, there is no evidence that it has ever become established in the flora (J. E. Arriagada 1998). Pulicaria vulgaris Gaertner was collected as a ballast weed in New Jersey in 1879. No other collections of the species from North America are known to me.