Neottia cordata, the lesser twayblade[2] or heartleaf twayblade,[3] is an orchid of upland bogs and mires that rarely exceeds 15 cm (5.9 in) in height. It was formerly placed in the genus Listera, but molecular phylogenetic studies have shown that Neottia nidus-avis, the bird's-nest orchid, evolved within the same group.[4]
It is never very common but may be frequently overlooked because of its small size and a tendency to grow underneath heather on sphagnum moss. The single erect flower-stem is often tinged red and is clasped near the base by a pair or ovate-orbicular glossy green leaves. The small flowers which look deceptively simple in structure for an orchid, are purple-green in colour with a somewhat swollen calyx.
Listera cordata was first described by Carolus Linnaeus in 1753, as Ophrys cordata. In 1813, Robert Brown identified O. cordata and O. ovata as members of a separate genus, Listera. Distomaea cordata (Linnaeus) Spenner was superseded by Bifolium cordatum (Linnaeus) Nieuwland.
It has a circumpolar distribution being found in Europe, Asia and large parts of North America. In the United Kingdom its distribution is largely western and northern, becoming most common in the western Highlands of Scotland, Snowdonia in Wales, and the Lake District in England.[5] (Codes) [6]
Listera cordata occurs in two apparently rather different habitats. On raw humus in damp to moist woodland, with a preference for spruce forest, in open wet heather moorland and in Sphagnum bogs. However, the two habitats may not really be so different, since the soil is usually acid in both habitats and the small plants in the open localities usually grow in the shelter of comparatively tall heather on north-facing slopes or in the wet Sphagnum of raised bogs.
Also grows in slightly to fairly damp places in pine, fir, and aspen forest at elevations between 9,000 and 10,300 feet (2,740 and 3,150 meters). It grows on flat to gently sloping terrain, usually in moderate to light shade. Often it grows in open forest in a habitat similar to that of Calypso bulbosa or Goodyera repens. The habitat appears slightly damper because of the relative abundance of herbaceous growth and perhaps the presence of slightly more mosses on the forest floor. Greater concentrations of plants accumulate near the edges of streams, seeps, and boggy areas. In these habitats, L. Cordata roots in mosses or damp duff.
The flowers produce nectar and are pollinated principally by fungus gnats in the groups Mycetophilidae and Sciaridae.[7]
Mycorrhizal partners are almost exclusively fungi in the Sebacinales clade Serendipitaceae. There may also be some association with Ceratobasidiaceae and/or Tulasnellaceae.[8][9]
Neottia cordata (as Listera cordata) from Bilder ur Nordens Flora Neottia cordata, the lesser twayblade or heartleaf twayblade, is an orchid of upland bogs and mires that rarely exceeds 15 cm (5.9 in) in height. It was formerly placed in the genus Listera, but molecular phylogenetic studies have shown that Neottia nidus-avis, the bird's-nest orchid, evolved within the same group.
It is never very common but may be frequently overlooked because of its small size and a tendency to grow underneath heather on sphagnum moss. The single erect flower-stem is often tinged red and is clasped near the base by a pair or ovate-orbicular glossy green leaves. The small flowers which look deceptively simple in structure for an orchid, are purple-green in colour with a somewhat swollen calyx.
