Rep. U.S. Mex. Bound. 2(1): 120. 1859.
Stems erect, 30–90 cm, hirsute to pilose, hairs glandular and eglandular. Leaves densely pilose; proximal 5–20 mm, margins 3-lobed, lobes 1 mm wide; distal 5–15 × 1 mm, margins entire. Inflorescences spikes, 1 (–4) -flowered; bract 1, 5–7 mm, 3-lobed, lobes green or purple, narrowly lanceolate. Pedicels: bracteoles 10–20 mm, margins entire. Flowers: calyx 10–17 mm, tube 2 mm, apex 2-fid, cleft 0.5–1 mm; corolla bright-yellow, 15–20 mm, throat 3–5 mm diam., abaxial lip 7–10 mm, shorter than adaxial and slightly spreading; stamens 4, filaments hairy, fertile pollen-sacs 1 per filament, vestigial pollen-sacs present. Capsules oblong-lanceoloid, 7–8 mm. Seeds 15–20, light-brown, reniform, 1.5–2 mm, reticulate and papillate. 2n = 26.
Phenology: Flowering Jul–Oct.
Habitat: Rocky slopes, mesas, often limestone.
Elevation: 1000–1900 m.
Ariz., N.Mex., Mexico (Sonora)
Cordylanthus laxiflorus is recognized by its bright yellow corollas with adaxial lip shorter than the galea. Cordylanthus parviflorus also has the abaxial lip shorter than the adaxial; it has pink to purple corollas.