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Common Herb Species of the Northwest Forest

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Listera cordata
Heart-leaved Twayblade
Orchidaceae (Orchid Family)

Heart-leaved Twayblade Description

General - a small, delicate perennial from slender creeping rhizomes; stems 6 - 20 cm tall, smooth or with a few gland-tipped hairs towards top.

Leaves - a single, opposite pair, at or below middle of stem, broad, heart-shaped, 1 - 4 cm long.

Flowers - 5 - 16 in long cluster at stem tip; pale green to purplish brown; sepals and petals 2 - 3 mm long; lip 3 - 6 mm long, tip split into 2 very narrow or lance-shaped lobes, 2 tin horn-like teeth at base; appearing early-summer.

Fruit -many-seeded, egg-shaped capsules, 4 - 6 mm long.; developing in early-summer.

Habitat

Dry to wet mossy woods, thickets and bogs; scattered across boreal forest north to Churchill, Manitoba, central Yukon and southern Alaska; circumpolar.

Notes

Heart-leaved Twayblade is our most common Listera but nonetheless it is an uncommon wildflower, small and easily overlooked The intricate pollination mechanisms of Listera species fascinated Charles Darwin, who studied them intensively. The pollen is blown out explosively within a drop of viscous fluid that glues the pollinia to unsuspecting insects (or to your finger if you touch the top of the column). This species is also called 'mannikin twayblade'. 'Mannikin' is from the Dutch manneken, which means 'little man' or 'dwarf'. The genus Listera is named in honour of Dr. Martin Lister, an English naturalist who lived from 1638 - 1711. The species name cordata means heart-shaped, in reference to the heart-shaped leaves.

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