Monday, November 15, 2010

Heart-leaved Twayblade (Listera cordata)

The Heart-leaved Twayblade is a very small plant with tiny, but intricate flowers.  With a bit of imagination the flowers look like a cloud of tiny green or red insects hovering around the flower spike and above the two opposite heart-shaped leaves.


The plant is supposed to grow as tall as 40 cm, but the plants we have seen have all been tiny, less than 15 cm tall.  The flowers, said to number up to forty, have been 15 or fewer on the plants we've seen and are only about 1 cm in size.

There are two varieties of this plant, variety cordata, more common in the Eastern United States and Canada and variety nephrophylla, more common in the west.  I have not yet figured out the difference between the two, except that the first variety is very tiny.

The species and especially variety cordata is very widespread being found not only throughout the USA and Canada but also in Europe and Asia.  Variety nephrophylla, however, is found only in the western USA and Canada, from the Rockies west to California and north to Alaska.

Both varieties come in red and green forms which further complicates the situation.  One cannot tell the variety simply from the colors of the flowers.  Both are very attractive, however, though I think the red flowered form is the more appealing.



In the pictures, in both cases, the first green and red flowered flowered plants were photographed in the North Cascades and the second in the Canadian Rockies in Berg Lake Provincial Park.  In the second location the red-flowered plants were also photographed growing among the green.



The first picture is of an plant with flowers intermediate in color, perhaps the offspring of the two different color forms.  This plant was photographed in the North Cascades in Washington State along the Heliotrope Ridge Trail.

2 comments:

  1. We've been in areas where they seem to be everywhere, but always only a few plants growing together - they seem to like their personal space.

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