2. Hieracium gronovii L. (beaked hawkweed)

H. gronovii var. foliosum Michx.

H. floridanum Britton

Pl. 256 a, b; Map 1068

Plants with a short, usually erect or ascending rootstock, rarely with a short, spreading rhizome. Stems mostly solitary, 30–85(–120) cm long, moderately to densely pubescent, at least toward the base, with light orangish brown, spreading to loosely ascending hairs 4–9 mm long having a bulbous or slightly expanded base, these sometimes becoming sparse or nearly absent toward the tip, usually also inconspicuously pubescent with cobwebby, minute, branched hairs, often also with sparse, gland-tipped hairs toward the tip. Basal leaves usually persistent at flowering, sessile to short-petiolate, the blade 3–20 cm long, narrowly oblanceolate to obovate, rounded to sharply pointed at the tip, the surfaces and margins pubescent with sparse to moderate, spreading, bulbous-based hairs and often also sparse to moderate, minute, inconspicuous, branched hairs. Stem leaves sometimes few and nearly basal, sometimes several and well spaced, similar to the basal leaves but gradually reduced in size, more often sessile, oblong-obovate to oblanceolate, the uppermost with the base often slightly clasping the stem. Inflorescences elongate cylindrical panicles or racemes. Involucre 6–9 mm long, the inner series of bracts narrowly oblong-lanceolate, pubescent with inconspicuous, cobwebby, branched hairs and sometimes also longer, spreading, usually dark-colored, gland-tipped hairs, the outer series much less than 1/2 as long as the inner series. Ligulate florets 20–40. Corollas 7–9 mm long, light yellow to yellow. Pappus bristles 4–5 mm long, light yellowish to orangish brown. Fruits 2.5–4.0 mm long, somewhat tapered to the slightly expanded tip. 2n=18. May–October.

Scattered, mostly south of the Missouri River, absent from all but the eastern portion of the Glaciated Plains Division (eastern U.S. west to Illinois, Kansas, and Texas; Canada, Mexico, Central America, Caribbean Islands). Mesic to dry upland forests, ledges and tops of bluffs, and borders of glades; also pastures, old fields, and roadsides.

There has been some controversy about the correct application of the name H. gronovii, but the epithet was conserved at an international botanical congress with a type specimen that fixes the application to the traditionally accepted widespread species (Greuter et al., 2000). Specimens with more stem leaves and relatively few-flowered inflorescences occasionally have been misdetermined as H. scabrum.

Steyermark (1963) corrected earlier reports for Missouri of the eastern H. venosum L., annotating the several specimens in question to H. gronovii based on their apically somewhat tapered (vs. cylindrical) fruits. This was confirmed during the present study. Hieracium venosum should continue to be excluded from the Missouri flora. Hieracium gronovii is relatively variable in plant height, as well as number and size of the stem leaves. One of these specimens, a historical collection from Newton County, has unusually narrow leaves and relatively long, spreading hairs. Possibly, it represents a hybrid with H. longipilum. In general, the two species do not grow together, but they are known to hybridize regularly in other parts of their ranges.