Annual or sometimes winter annual.
Reproducing only by seed.
Stems (Fig 6) of flowering plants 20cm-1m high, erect, often much-branched near the top but always single (A) at the ground surface because they start from seed each year, often with remnants of the cotyledons (seed leaves) still visible (a).
Opposite (2 per node), tapering towards both ends, lower ones widest near the tip (A), middle and upper ones widest nearer the stem (B); upper leaves and stem branches densely sticky-hairy (Fig 7).
Flowers showy and usually opening in the evening but often open throughout the next day as well. The sepals are light green, united to form a calyx tube (Fig 4,5,b) with 5 prominent veins (c) lined up with the 5 long-tapered teeth (d), and 5 less prominent but distinctly branched veins (e). The petals are white, creamy-white or pinkish, flaring outwards in a circle 1-3cm in diameter, each petal deeply lobed (f). Flowers are bisexual, having 10 stamens and 1 pistil, although rarely some may be unisexual. The pistil with 3 long styles, becoming an ovoid seedpod which usually opens with 6 teeth (g) and scatters many kidney-shaped, small (0.8-1mm), grayish-orange, rough seeds. Flowers from June to August.
Slender taproot with fine branches.
Night-flowering catchfly grows in much the same situations as White cockle but is more common in cultivated fields and is more widespread through northern Ontario.
It is distinguished by its dense covering of sticky hair on upper stems, leaves and calyx, its calyx with long-tapered teeth (Fig 4, d) and 10 distinctly branching lengthwise veins (c,e) clearly visible as the seedpod expands inside, its seedpod opening by usually 6 teeth (Fig 4, g), and its annual or winter annual habit. Very similar in general appearance to White cockle; seedlings nearly identical but are somewhat sticky-hairy.
(A) Base of annual plant. (B) Flowering stem. (C) Seedpod with 6 teeth.
Night-flowering catchfly plant.
Night-flowering catchfly seedpod.
Stem of night-flowering catchfly.
Leaves of night-flowering catchfly.