Silene antirrhina L., sleepy catchfly, sleepy silene, snapdragon campion. Annual, taprooted, 1—several–stemmed at base, principal shoots of tall individual often unbranched below flowers, erect, in range 20—50(—75) cm tall; shoots typically densely puberulent at base and upper plant glabrous, with bands of viscid hairs on upper internodes, peduncles, and inflorescence branches, the viscid bands 10—20 mm long, dark reddish, unscented.
Stems mostly cylindric but 2–ridged below each node, to 2 mm diameter (lower nodes), with each ridge short–descending from leaf, tough, swollen and often purplish just above node for each branch.
Leaves opposite decussate, simple, short–petiolate (basal leaves) and sessile (cauline leaves) with pairs fused across node, without stipules; petiole 2—5 mm long, expanded at base, ciliate on margins; blade of basal leaves spatulate to oblanceolate, 14—45 × 5.4—6.8(—8.5) mm, tapered at base, entire and ciliate on margins, obtuse to acute at tip, with midrib conspicuous and raised on lower surface, pubescent; blade of cauline leaves oblanceolate to elliptic–linear or linear, 10—40 × 1.5—5 mm, flat to somewhat folded along midrib, narrowly tapered to tapered at base, entire and ciliate on margins, acute to acuminate at tip, upper surface glabrous, lower surface pubescent.
Inflorescence dichasial cyme, terminal and axillary, open, typically forked 3—4 times, flowers erect, bracteate; peduncle to 100 mm long; bracts subtending each fork 2 and fused across node, leaflike, linear to lanceolate–linear, < 20 × 1—2 mm, reduced upward; pedicel straight, at anthesis ca. 10 mm long increasing 3—5× in fruit.
Flower bisexual, radial, 5—8 mm across; receptacle extending above calyx as stalk (stipe) fused to and surrounding stalk of ovary (gynophore); calyx 5–lobed, ± lanceoloid but constricted at base, bell–shaped around stipe, 6—8 × 2.5—3 mm, expanding to 4—4.5(—5) mm wide in fruit; tube conspicuously 10–veined, the veins green and raised with 1 extending to each lobe, becoming scabrous, the furrows membranous, glabrous; lobes erect, ovate–deltate, 1—1.5 mm long, often lavender or purplish, acute to acuminate at tip with overlapping margins, membranous, ciliate; petals 5, arising from stipe below stamens, clawed, glabrous; claw = calyx, to 2 mm wide, tapered to narrow at base, 3–veined, translucent–white, winglike and colorless on margins, glabrous at base; limb spreading, 2–lobed to heart–shaped, 3—4.5 × 2.5—3 mm, lobes ca. 0.5 mm long, pinkish rose (white) above, dark purple–veined on back, with a pair of minute white bumps (= vestigial appendages) below sinus near the base; stamens 10 in 2 whorls, 1 whorl long and free, other whorl short and fused to bases of petals, included; filaments arising from rim of stipe, cylindric, ca. 3 and 4 mm long, translucent–white, glabrous; anthers dorsifixed, dithecal, 0.5—0.8 mm long, conspicuously shorter on short stamens, creamy white, anthers of longer stamens at level of stigmas, longitudinally dehiscent; pollen white; pistil 1, gynophore 1 mm long or more as fruit matures; ovary superior, narrowly ovoid, 3—3.5 mm long, green, rounded at tip, glabrous, 3–chambered below midpoint and 1–chambered above, each chamber with many ovules attached to center; styles 3, included, ascending, 1 mm long not increasing in fruit, translucent–white, stigmatic along most length, persistent.
Fruit capsule, dehiscent by 6 recurved teeth at tip, hidden by calyx, many–seeded, short–stalked, narrowly ovoid, 6.5—7 × 3—4 mm, smooth or somewhat 3–sided with dimpled sides, glabrous, with tip even with persistent calyx; stalk glabrous.
SeedD–shaped to kidney–shaped compressed with sunken sides, 0.6—0.8 × 0.4—0.5 × 0.5 mm, dull dark brown, back with 4 rows of minutely bumpy (collicullate) or papillate cells and ± 4 concentric tiers of cells on sides.
A. C. Gibson & B. A. Prigge