Ontario Weeds: Pennsylvania smartweed
Excerpt from Publication 505, Ontario Weeds, Order this publication
Table of Contents
- Other Names
- General Description
- Flowers and Fruit
- Similar Species
- Related Links
Lady's Thumb. A. Plant. B. Portion of stem with leafstalk and ocrea. Pale smartweed. C. Portion of stem with lower surface of leaf blade, leafstalk and ocrea. Pennsylvania smartweed. D. Portion of lower stem with leafstalk and ocrea. E. Portion of upper stem with leaf stalk and ocrea showing stalked glands.
Leaves: Distinguished from Pale smartweed by the absence of matted whitish hair on the undersurface of lower leaves although a few, scattered, short, straight hairs may be present; by the absence of, or only occasional presence of tiny yellowish, unstalked glands on the undersurfaces of upper leaves; by the presence of orange to red or purplish, distinctly stalked glands (glandular hairs) on the upper stems below and in the flower spikes.
Flowers & Fruit: Distinguished from Pale smartweed by the deep pink to reddish colour of the flowering spikes; and by the larger "seeds" that are round-ovate, flattened, slightly hollowed on one side but not the other, and about 3mm (1/8in.) long by 2.5mm (1/10in.) wide; their larger size giving the spikes a coarser texture than in Pale smartweed. Flowers from July to September.
Similar Species: It is distinguished from lady's-thumb by the complete absence of hair from the surface of the ocrea, the complete absence of a fringe of hair from the margin of the ocrea, the presence of stalked glands on the upper stems, and by its coarser spikes and larger seeds.
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