The genus Listera is named for Martin Lister, a noted English physician and naturalist. (NB. This is not the same doctor who pioneered the use of antiseptic. Dr. Martin liked to mess around in dirty, old bogs) The species name is derived from the Latin "cordatus", meaning heart-shaped, in reference to the leaves.

This inconspicuous, little orchid is missed by all but the most careful observers. It is usually no more than six inches tall. Two small, opposite heart-shaped leaves are found halfway up the flimsy stem. This feature distinguishes it from all the other "little-green-job" orchids, they only have one leaf.

The flowers appear in July and August but you really need a magnifying glass to see them. (A flashlight wouldn't hurt, either.) Clustered near the top of the spike, the 6-20 tiny flowers have many interesting features. The few that I have examined, were always whitish-green in color but apparently there are purple ones as well. The long lip is split in two, halfway up its length, unlike the other twayblades. The plant doesn't last long. It grows so fast the ovaries often split and spill their seeds before the flowers wither.

Darwin, among other naturalists, was fascinated by the interesting pollination mechanism, involving a kind of quick-drying glue. It is believed to be pollinated by small insects like fungus gnats. Luer, in his book, on the Orchids of North America (1976) goes into some detail on this subject. The seedpods are hard to find because the flower spike is so fragile they usually break off. The ones I have seen had a few round pods clustered near the top of the stem.

Heart-leaved Twayblade is usually found growing in moss in northern, coniferous bogs. It prefers cedar bogs with underlying clay. Much more common in the north, than in the south, it is found in Europe and Asia as well as North America. There are two other Twayblade species found in northern Manitoba.