Ontario Weeds: Flower-of-an-hour
Excerpt from Publication 505, Ontario Weeds, Order this publication
Table of Contents
Flower-of-an-hour. A Top of plant. B. Seedling.
Leaves: Leaves alternate (1 per node), leaf-stalks about as long as the blades, leaf blades deeply 3-parted with each division coarsely lobed.
Flowers & Fruit: Flowers 2-4cm (3/4 - 1 1/2in.) in diameter with a ring of several linear bracts below the calyx; calyx of 5 papery-thin united sepals, coarsely hairy on the promnent, purplish, lengthwise veins; petals yellowish with dark or purplish-brown centre or eye; filaments united into a central column; seedpod globular, opening at the top, with many purplish-brown, V-shaped seeds about 2mm (1/12in.) long. Flowers from July to late autumn.
Habitat: Flower-of-an-hour occurs only in the southwestern part of southern Ontario where it is a frequent weed in row crops, open fields and waste places.
Similar Species: It is distinguished by its low branching habit, bluish-green leaves which are deeply 3-parted and coarsely toothed, yellow flowers with a purplish-brown eye spot, a cluster of linear bracts immediately below the calyx, and the purple-veined papery calyx enclosing the globular seedpod.
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