Calyptocarpus vialis Less., straggler daisy, prostrate lawnflower. Perennial herb, taprooted, not rosetted, 1–stemmed at base, 4—27 cm tall, to 40 cm long; gymnomonoecious; shoots with only cauline leaves, strigose and short–strigose, minutely scabrous, the hairs with minute projections.
Stems ± cylindric, 1—1.4 mm diameter, tough, green and sometimes finely red–striped, enlarged at nodes, internodes to 85 mm long, often > associated leaf, short–stigose with upward–pointing hairs.
Leaves opposite decussate, simple, petiolate ± fused as ledges across node, without stipules; petiole to 4 mm long, crescent–shaped in ×–section, indistinct from blade; blade ovate to broadly lanceolate or deltate, 6.5—54 × < 5—28 mm, slender tapered to petiole from broad taper, low–serrate on margins, broadly acute to obtuse at tip, 3–veined close to base but pinnately veined, lateral veins ± sunken on upper surface and principal veins raised on lower surface, both surfaces with evenly distributed short–strigose hairs pointing upward and toward margins, sometimes with several longer hairs at petiole–blade junction.
Inflorescence head solitary and subsessile with 2 lateral branches at base, 1 continuing shoot and other much delayed, head radiate, 4—8 mm across, with 2—9 pistillate ray flowers and 10—25 bisexual disc flowers, bracteate; peduncle < 1 mm long; involucre bell–shaped, ca. 5—6 × 3.5—5 mm (expanding in fruit), green, of 4—6 helically alternate, overlapping phyllaries, phyllaries obovate, 5—6 × 2—2.5 mm, conspicuously short–ciliate with upward–pointing hairs and scabrous or outer phyllaries short–strigose with several radiating, longer hirsute hairs, persistent, in flower awns visible above involucre; receptacle narrow and convex, with bractlets (paleae) subtending inner ray flowers and disc flowers, bractlet scarious, ca. 4 mm long, of outer flowers narrowly elliptic to oblong and ± flat, of inner flowers linear and often keeled, short–ciliate to minutely ciliate and jagged on margins, outer bractlets with short hairs on outer surface above midpoint.
Ray flower bilateral, 1.1—1.5 mm across; calyx (pappus) 2—5+, spinelike with upward–pointing barbs, ascending to suberect and unequal in ring, green, 2 awns at least 2—2.7 mm long, 1—3 awns much shorter + inconspicuous awns not clearly viewed; corolla 2—3 lobed (unlobed); tube cylindric, 1 × 0.2 mm, white, glabrous; limb somewhat obovate in outline with lobes shallow or sinuses < 1 mm, 2—3.2 × 0.8—1.8 mm long, bright yellow, short–hairy on lower surface to midpoint; stamens absent; pistil 1; ovary inferior, 3–sided or 2–sided strongly flattened front–to–back, truncate at top tapered to base, 3 × 1 mm, lateral sides wider than back, white, covered with ascending short hairs and inconspicuous glandular hairs, 1–chambered with 1 ovule; style exserted, ca. 3 mm long, colorless at base to orange–yellow above midpoint, 2–branched, the stigmatic branches fully exserted, spreading, ca. 1 mm long
Disc flower radial, ca. 1 mm across; calyx (pappus) 2—5+, spinelike with upward–pointing barbs, ascending to suberect and unequal in ring, green, 2 awns at least 2—2.7 mm long, 1—3 awns much shorter + inconspicuous awns not clearly viewed; corolla 4(—5)–lobed, 2.2—2.4 mm long, glabrous; tube cylindric, colorless, 0.8—1 mm long; throat narrowly funnel–shaped, ca. 1 × 0.6—0.7 mm, yellowish with 4 veins; lobes suberect, triangular to deltate, ca. 0.4 mm long, golden yellow; stamens 4(—5), attached at top of corolla tube; filaments ca. 0.8 mm long, colorless; anthers fused into cylindric surrounding style, basifixed, dithecal, ca. 1 mm long with appendages, reddish, longitudinally dehiscent; pollen golden yellow; pistil 1; ovary inferior, strongly flattened, truncate at top tapered to base, ca. 3 × 1 mm, white, covered with ascending short hairs and inconspicuous glandular hairs, 1–chambered with 1 ovule; style ca. 3 mm long, colorless at base to golden yellow above, 2–branched, the stigmatic branches exserted, spreading, 0.8—1 mm long.
Fruits cypselae (achenes), with awns, ± monomorphic; fruit body obovate strongly flattened front–to–back, 3—4 × 0.9—1.6 mm, mostly light brown (green when immature), of ray flowers flattened on both faces, of disc flowers inner face somewhat concave and outer face often convex or ± with midridge, with whitish callus at base, pubescent initially with short–stalked glandular hairs; awns 2—5+, spinelike with upward–pointing barbs, ascending to suberect and unequal in ring, whitish, 2 at least 2—2.7 mm long, 1—3 awns much shorter + inconspicuous awns not clearly viewed, awns persistent.
A. C. Gibson