Flora of North America species comparison

erect, branches 1–several from base, unbranched proximal to inflorescence.

proximal 4–10 pairs opposite, distal alternate, erect to spreading;

stipular glands absent;

blade of proximal leaves spatulate, central and distal elliptic, oblanceolate, or obovate, 15–25 × 3–7 mm, margins entire, not ciliate, apex acute to apiculate.

alternate, opposite, or whorled, simple;

stipules absent or present as small, dark, spheric glands;

petiole usually absent, rarely present;

blade margins entire, serrate, or denticulate;

venation pinnate.

corymbs.

terminal, racemes, panicles, or cymes (rarely thyrses or corymbs in Linum) [spikes].

1–10 mm.

sepals persistent, lanceolate-ovate, inner shorter, broader, thinner than outer, outer sepals 2–4 mm, margins not scarious, inner sepals usually with a few small, sessile glands along margin distal to middle, rarely eglandular, outer ones entire, apex acute to acuminate;

petals yellow, obovate (sometimes notched at apex), 3–5.5 mm;

stamens 1.2–3 mm;

anthers 0.5–1 mm;

staminodia absent;

styles distinct, 1–2 mm;

stigmas capitate.

bisexual;

perianth and androecium hypogynous;

hypanthium absent;

sepals 4–5, connate basally [distinct];

petals 4–5, distinct or coherent basally, imbricate or convolute, bases sometimes with appendages;

nectary extrastaminal;

stamens 4–5 [10], connate basally, filament tube and petal bases adherent or adnate [free];

anthers dehiscing by longitudinal slits;

pistil 1, 2–5-carpellate, ovary superior, 4–5-locular, placentation axile or apical-axile;

ovules 2 per locule, anatropous;

styles 2–5, distinct or partly connate;

stigmas 2–5.

capsules, dehiscence septicidal, or indehiscent or schizocarps breaking into 4 nutlets (Sclerolinon).

globose, carpels flattened or ± concave abaxially, 1.3–1.8 × 2–2.5 mm, apex depressed, dehiscing freely into 10, 1-seeded segments, segments falling freely, false septa nearly complete, proximal margins usually sparsely and inconspicuously few-ciliate.

1–1.5 × 0.6–0.9 mm.

2 per locule, seed coat often mucilaginous.

= 36.