8. Pedicularis L. (lousewort)

Plants perennial herbs, with fibrous roots (tuberous-rooted elsewhere), sometimes with rhizomes or stolons, hemiparasitic, often lacking a well-developed taproot, olive green to green or dark green, sometimes purplish-tinged, sometimes blackening upon drying. Stems solitary to several, unbranched or with short branches near the tip, erect or ascending, rounded or sometimes slightly ridged from the leaf bases, usually glabrous or nearly so toward the base, progressively more pubescent toward the tip with relatively stout, multicellular, nonglandular hairs, the upper portions and inflorescence axes often densely hairy or appearing woolly. Leaves alternate or opposite, sometimes also basal, lowermost stem leaves variously long-petiolate or short-petiolate to sessile, those of the upper nodes short-petiolate to sessile. Leaf blades narrowly oblong-elliptic to lanceolate or oblanceolate, moderately to deeply pinnately divided or lobed into 13–35 lobes or the uppermost merely coarsely toothed, the lobes oblong to ovate, toothed and/or lobed along the margins, mostly rounded at the tips. Inflorescences relatively dense, short to elongate, terminal (often also appearing axillary in P. lanceolata) spikes or spikelike racemes with at least the lowermost bracts more or less leafy (reduced progressively toward the axis tip), the flowers solitary in the axil of each bract; sessile or very short-stalked, lacking bractlets. Cleistogamous flowers absent. Calyces strongly bilabiate, oblique at the tip, bell-shaped to more commonly more or less tubular, the lips variously toothed or with 2 variously shaped lobes (4 or 5 teeth or lobes elsewhere), persistent, not or only slightly enlarged at fruiting. Corollas 15–27 mm long, strongly bilabiate, white or yellow, sometimes partially pinkish-, reddish-, or purplish-tinged or at least the upper lip dark purple, the upper lip fused into a hooded or helmet-shaped structure, this with a pair of small teeth near the otherwise truncate tip or unlobed and tapered to a beaklike tip, the lower lip slightly shorter than the upper one, ascending or spreading, 3-lobed, longitudinally grooved between the lobes, the tube in our species usually somewhat arched or curved, hairy on the inner surface (at least near the base), the hairs not blocking the throat, the lobes glabrous. Stamens hidden under the upper corolla lip, the filaments of 2 lengths, hairy near the base, the anthers with 2 sacs, these parallel, blunt at the ends, light yellow, glabrous. Style curved under the upper corolla lip, sometimes slightly exserted, the stigmatic portion small, capitate, unlobed. Fruits (in our species) 8–17 mm long, obliquely ovoid to more or less oblong-ovoid, glabrous. Seeds asymmetrically oblong to oblong-ovoid, sometimes winged, the surface with a fine to very fine network of sometimes faint ridges and pits, yellowish brown to brown or dark brown. About 500 species, North America, South America, Europe, Asia.

The Missouri species of Pedicularis have very large host ranges that include both herbaceous and woody species (Piehl, 1963). Lackney (1981) showed that plants of P. lanceolata could even be cultivated in pots successfully on the roots of wheat and red clover.