3. Hieracium longipilum Torr. (long-haired hawkweed)

Pl. 256 f, g; Map 1069

Plants with a short, ascending to spreading, occasionally branched rootstock. Stems mostly solitary, 50–170 cm long, densely pubescent with white to light orangish brown, spreading to loosely ascending hairs (8–)10–20 mm long (rarely longer) having a bulbous or slightly expanded base, these becoming sparser toward the tip, usually also inconspicuously pubescent with cobwebby, minute, branched hairs, often also with sparse, gland-tipped hairs toward the tip. Basal leaves often persistent at flowering, mostly short-petiolate, the blade 5–30 cm long, narrowly oblanceolate to oblanceolate, rarely obovate, rounded to sharply pointed at the tip, the surfaces and margins pubescent with dense, more or less spreading, bulbous-based hairs (these sometimes somewhat shorter than those of the stem) and rarely also sparse, minute, inconspicuous, branched hairs. Stem leaves usually several, similar to the basal leaves but gradually reduced in size, more often sessile, oblanceolate to narrowly oblanceolate, the base usually not clasping the stem. Inflorescences usually elongate cylindrical panicles, occasionally only spikelike racemes. Involucre 7–10 mm long, the inner series of bracts narrowly oblong-lanceolate, pubescent with inconspicuous, cobwebby, branched hairs and longer, spreading, usually dark-colored, gland-tipped hairs, the outer series variable and grading into the inner series, some of the bracts more than 1/2 as long as those of the inner series. Ligulate florets 40–90. Corollas 7–9 mm long, yellow. Pappus bristles 5–7 mm long, light yellowish to orangish brown. Fruits 3.0–4.5 mm long, somewhat tapered to the slightly expanded tip. 2n=18. May–October.

Scattered in a broad band from southwestern to northeastern Missouri, absent from most of the northwestern and southeastern quarters of the state (Minnesota to Texas east to Ohio, Tennessee, and Louisiana; Canada). Upland prairies and openings of dry upland forests; also old fields, railroads, and roadsides.

Plants with the involucres mostly or entirely pubescent with inconspicuous, nonglandular hairs have been called f. eglandulosum E.J. Palmer & Steyerm., but, as noted by Deardorff (1977) and others, patterns of pubescence are too complex and variable in this genus to provide stable characters for subdivision of species.