Linum berlandieri Hooker var. berlandieri, Berlandier flax. Annual, taprooted, often 1(—2)–stemmed at base but appearing several–stemmed with whorled principal shoots within 35 mm of root, with ascending shoots each with terminal inflorescence, in range mostly to 20 cm tall; shoots with ascending cauline leaves, having short, stalked glands.
Stems of green stems ca. 10–ridged, to 1.5 mm diameter, with 3 colorless, winglike ridges descending from each leaf and stipules, tough, internodes 1—2 mm long, having minute glandular hairs along ridges, of basal stem cylindric with brown and purple–red periderm having vertical lines of minute glandular hairs.
Leaves helically alternate (opposite or whorled at certain basal nodes), simple, sessile, with stipules; stipules 2, at base of leaf on stem, domelike and glandular, 0.2—0.3 mm long, reddish; blade lanceolate–linear (narrowly elliptic to narrowly oblanceolate), 5—20 × (1.3—)2—3 mm (first–formed leaves < 2 mm long), tapered at base (not clasping), entire and minutely toothed on margins, acuminate with short point at tip, 1–veined from base with midrib raised on both surfaces, glabrous and glaucous.
Inflorescence panicle of racemelike cymes, terminal, open and somewhat flat–topped, lateral branches helically alternate and ascending, forked or unforked and several–flowered, inflorescence mostly < 10–flowered, bracteate; bract subtending each branchlet, leaflike, decreasing upward, each with 2 minute stipules, with glandular teeth on margins, midrib raised more on lower surface, with point at tip often reddish, minutely beaded; branchlet axes conspicuously ridged; bractlet subtending pedicel awl–shaped, to 5.5 mm long, with 2 stipules at base, 1–veined with glandular teeth along midvein and margins, bristle 0.5—0.6 mm long; pedicel ca. 7–ridged, at anthesis 5.5—10 mm long increasing in fruit, winglike ridges abruptly constricted approaching calyx, pedicel enlarged above constriction but ridges continuous on exposed sepals.
Flower bisexual, radial, 21—25 mm across, open and dishlike in morning, closing before afternoon with petals readily abscising; buds and flowers after petals abscised lanceoloid; sepals 5, helically alternate, firmly attached to receptacle, while open ascending and appressed to corolla later erect, overlapping below midpoint, subequal, acuminate–lanceolate with bristle point < 1 mm long, (6.5—)7.8—9 × 1.7—2.7 mm decreasing slightly from outer sepal to inner sepal, increasing slightly in fruit, green but the inner sepal having colorless portions below midpoint, having tip colorless or aging orangish and purple–red at base, margins colorless, conspicuously 3–veined, margins and raised midvein with glandular teeth having greenish heads; petals 5, spreading, attached to base of short stamen tube, twisted in bud with overlapping limbs, short–clawed, easily dislodged, in bud yellow and apricot; claw inverted deltate, to 2 mm, white, with tuft of short white hair 1 mm from base on upper surface; limb fan–shaped, 11—13.5 × 10—11 mm, broadly rounded and sometimes notched at tip, yellow and yellow–orange to apricot with 12+ radiating orange to red–orange veins, the orange pigment to 2/3, especially veins glossy; stamens 5, fused at their bases forming a ringlike tube around ovary base appressed to ovary; tube 1 mm long, white, with minute tooth in each sinus between filaments (vestigial staminodes); filaments ca. 5 mm long, white base–to–tip; anthers dorsifixed, dithecal, ± 2 mm long, orange–yellow, longitudinally dehiscent; pollen orange–yellow; nectaries 5, fused to stamen tube opposite filament bases; pistil 1, erect, 9.5—10 mm long; ovary superior, smoothly ovoid, ca. 1.2 × 1 mm, lacking strongly 5–angled beak, green but whitish at base, inconspicuously striped and veined, 5–chambered becoming falsely 10–chambered by growth of false septa, with 2 ovules per chamber; styles fused most of length, 5–branched, white at base then yellowish becoming yellow–orange below midpoint, the branches erect to ascending ca. 1.3 mm from end of column, short–papillate, exserted several mm above anthers and exposed ca. 2.5 mm after petals lost and calyx tightly closed; stigmas capitate, ± 0.35 mm across, cream–colored, conspicuously papillate.
Fruit capsule, schizocarpic, septicidal, 10–seeded, breaking into 5 crescent–shaped, 1—2–seeded segments, ovoid, 3.8—4.3 × 2.6—3.3 mm, tan; often with dried staminal ring and filaments at base.
Seed persistent in thick–walled fruit segment between papery divisions, flattened ovoid, ca. 2.5 × 1.2 mm, orange–brown and somewhat glossy, with outlines of cells on seed coat.
A. C. Gibson