Flora of North America species comparison

broadly lanceolate to oblong-lanceolate, sometimes amplectant, usually abruptly narrowed from distinct, asymmetric shoulders, 1–2.2 × 0.17–0.5 mm;

margins serrate, commonly spinose at the shoulders, with one shoulder more deeply incised and less regularly spinose or dentate than the other;

apex subulate, sharply pointed, and sometimes recurved;

costa occasionally absent at the base, strong distally, percurrent, excurrent, or ending near the apex, toothed abaxially;

areolation lax in proximal third, more compact distally;

median laminal cells usually in diagonal rows upward from costa to margin, smooth;

distal laminal cells smooth.

lanceolate, broadly linear or ligulate, acuminate, sometimes narrowed distally from shoulders, 0.8–2.5 × 0.15–0.4 mm;

margins serrulate or serrate, with teeth sometimes recurved up to 45°;

apex acuminate and papillose;

costa at the base thin or not always apparent, stronger distally, often filling the acumen, percurrent or excurrent, papillose;

areolation firm proximally and distally compact to dense;

median laminal cells in ± vertical rows, smooth or slightly papillose;

distal laminal cells papillose.

with columella occasionally persisting to maturity;

stomates scattered throughout.

with columella resorbed before meiosis;

stomates in proximal half or scattered throughout.

spherical or reniform, 47–95 × 40–62 µm.

various, 43–120 × 35–80 µm.