[oregonflora.org] Description, Habitat: Plants 5 to 30 cm.
Stems primary axis often ill-defined, branches erect to ascending, slender, densely appressed strigose and sometimes sparsely spreading-hirsute.
Leaves linear to lanceolate, 10 to 40(50) × 1 to 3 mm, tips rounded to obtuse, surfaces appressed- to ascending-hirsute, coarser hairs pustulose, pustules larger on margins and abaxial surfaces.
Inflorescences cymules solitary or paired, occasionally crowded, elongating to 5 to 9 cm, proximal-most flowers usually not touching; bracts absent; pedicels 0.5 to 1 mm in fruit.
Flowers ascending to usually appressed, usually persistent at maturity; calyces symmetric, cylindric, bases rounded, constricted below tip, 1.5 to 2.5 mm at anthesis, 4 to 6 mm in fruit, lobes separate to base, linear to narrowly lanceolate, one lobe usually longer, margins densely ascending fine-hirsute, midribs thickened, spreading coarse-hirsute proximally, hairs pustule-based, tips erect to slightly recurved, abaxial surfaces ascending white-hirsute, adaxial surfaces glabrous proximally, appressed short-hirsute near tip; corollas rotate to funnelform, tubes 1.5 to 2 mm, limbs 1 to 1.5 mm in diameter; fornices absent; gynobases extending to 75% and styles to 100% length of mature nutlets; flower bracts absent.
Fruits 4, homomorphic, lanceolate to lance-ovate, 1.6?2.1 mm, gray with brown mottling, bases truncate, margins somewhat sharp angled at base, tips narrowly acute to acuminate, surfaces minutely tuberculate-spinulose, spinules ascending, sharp-tipped, abaxial surfaces low convex, spinal ridges absent, adaxial surfaces flattened, attachment scars centered, edges not raised, abutted entire length or narrowly gapped proximally, gradually bifid-forked and flare-gapped at extreme base.
Sandy, clay, or talus substrate, slopes or flats, shrublands, woodlands. Flowering Jun?Jul. 1200?1600 m. BR, Owy. CA, ID, NV, WA; east to WY. Native.
Cryptantha scoparia can be readily identified by its nutlet morphology, the four nutlets per fruit having a distinctive tuberculate-spinulose sculpturing, the spinules ascending and sharp-tipped. (contributed by Mary Ann Machi)