# Somatochlora

Somatochlora, or the striped emeralds, is a genus of dragonflies in the family Corduliidae with 42 described species found across the Northern Hemisphere.

## Taxonomy

The name Somatochlora is derived from the Greek soma (body) and khloros (green). The species Corduliochlora borisi was formerly treated as a member of Somatochlora.

## Description

Members of this genus are medium-sized dragonflies with dark bodies and a metallic green lustre. The eyes are brilliant green, and many species have dull to bright yellow markings on the thorax and/or abdomen. The abdomens of males are distinctive, with the first two segments bulbous-shaped, the third constricted, and the rest of the abdomen club-shaped with a straight ending. Females have abdomens with straighter sides. Identifying these dragonflies to species can be difficult. The cerci of males, on the tip of the abdomen, are distinctively shaped in each species, as are the subgenital plates on female abdomens. In some species, the subgenital plate is large and projecting, and is used as a "pseudo-ovipositor" for inserting eggs into a substrate.

## Distribution

Somatochlora species are found across the Northern Hemisphere in Europe, Asia, and North America, with some species extending into arctic regions north of the treeline. Some species extend south to Spain, Turkey, northern India, northern Vietnam, Taiwan and the Southern United States. At least one species, S. semicircularis, may be found at altitudes up to 3,700 m (12,100 ft). In North America, most species live in the boreal forest and/or the Appalachian Mountains.

## Life history

Somatochlora larvae typically live in bogs, fens, and/or forest streams, with some species found in lakes. They do not occur in marshy ponds. Many species are limited to very specific habitats and are rare and local. Adults feed in flight and may occur at some distance from their breeding habitat in mixed swarms.

## Species

Somatochlora is the most diverse group within the Corduliidae. Of the 42 described species listed below, 25 are North American, 16 are Eurasian, and one is circumboreal (S. sahlbergi). Two additional fossil species have been assigned to this genus: S. brisaci, based on a wing from the Upper Miocene in France, and S. oregonica, based on two wings from the Oligocene in Oregon.
| Species | Common Name(s) | Distribution |
| Somatochlora albicincta (Burmeister, 1839) | ringed emerald | Canada, northern United States |
| Somatochlora alpestris (Selys, 1840) | alpine emerald | Europe and Asia |
| Somatochlora arctica (Zetterstedt, 1840) | northern emerald | Europe and Asia |
| Somatochlora brevicincta Robert, 1954 | Quebec emerald | Canada, northern United States |
| Somatochlora calverti Williamson & Gloyd, 1933 | Calvert's emerald | southeastern United States |
| Somatochlora cingulata (Selys, 1871) | lake emerald | Canada, northern United States |
| Somatochlora clavata Oguma, 1922 | | Japan and Korea |
| Somatochlora daviesi Lieftinck, 1977 | | Bhutan, Nepal, and India |
| Somatochlora dido Needham, 1930 | | China and Vietnam |
| Somatochlora elongata (Scudder, 1866) | ski-tipped emerald, ski-tailed emerald | northeastern North America |
| Somatochlora ensigera Martin, 1907 | plains emerald | central North America |
| Somatochlora exuberata Bartenev, 1910 | Japan and eastern Russia |
| Somatochlora filosa (Hagen, 1861) | fine-lined emerald | southeastern United States |
| Somatochlora flavomaculata (Vander Linden, 1825) | yellow-spotted emerald | Europe |
| Somatochlora forcipata (Scudder, 1866) | forcipate emerald | Canada, northern United States |
| Somatochlora franklini (Selys, 1878) | delicate emerald | Canada, northern United States |
| Somatochlora georgiana Walker, 1925 | coppery emerald | eastern United States |
| Somatochlora graeseri Selys, 1887 | | east Asia |
| Somatochlora hineana Williamson, 1931 | Hine's emerald | Ontario and midwest United States |
| Somatochlora hudsonica (Hagen in Selys, 1871) | Hudsonian emerald | western and central Canada, northwestern United States |
| Somatochlora incurvata Walker, 1918 | incurvate emerald | northeastern North America |
| Somatochlora kennedyi Walker, 1918 | Kennedy's emerald | Canada, northeastern United States |
| Somatochlora linearis (Hagen, 1861) | mocha emerald | eastern North America |
| Somatochlora lingyinensis Zhou & Wa, 1979 | | Zhejiang |
| Somatochlora margarita Donnelly, 1962 | Texas emerald | Texas and Louisiana |
| Somatochlora meridionalis Nielsen, 1935 | Balkan emerald | southeastern Europe |
| Somatochlora metallica (Vander Linden, 1825) | brilliant emerald | Europe |
| Somatochlora minor Calvert, 1898 | ocellated emerald | Canada, northern United States |
| Somatochlora ozarkensis Bird, 1933 | Ozark emerald | Arkansas, Kansas, Missouri and Oklahoma |
| Somatochlora provocans Calvert, 1903 | treetop emerald | southeastern United States |
| Somatochlora sahlbergi Trybom, 1889 | treeline emerald | northwestern Canada, Alaska, northern Russia, Scandinavia |
| Somatochlora semicircularis (Selys, 1871) | mountain emerald | western North America |
| Somatochlora septentrionalis (Hagen, 1861) | muskeg emerald | Canada |
| Somatochlora shanxiensis Zhu & Zhang, 1999 | | Hubei, Shanxi |
| Somatochlora shennong Zhang, Vogt & Cai, 2014 | | Guangxi, Hubei |
| Somatochlora taiwana Inoue & Yokota 2001 | | Taiwan |
| Somatochlora tenebrosa (Say, 1840) | clamp-tipped emerald | eastern North America |
| Somatochlora uchidai Förster, 1909 | | Japan, China and Russia |
| Somatochlora viridiaenea (Uhler, 1858) | | Japan, eastern Russia |
| Somatochlora walshii (Scudder, 1866) | brush-tipped emerald | Canada, northern United States |
| Somatochlora whitehousei Walker, 1925 | Whitehouse's emerald | Canada, northwestern United States |
| Somatochlora williamsoni Walker, 1907 | Williamson's emerald | eastern North America |