The species of this genus are all well marked, and adult males are easily distinguishable. In all, blue forms a prominent feature. Three well-marked species are known, with a fourth less distinct. The females are duller in color than the males. The young are spotted and streaked with white.
Synopsis of Species.
Common Characters. Rich blue above, duller in the female. Beneath reddish or blue in the male, reddish or light drab in the female. Young with wings and tails only blue, the head and anterior parts of body with numerous whitish spots.
A. Breast reddish, or chestnut.
1. S. sialis. No chestnut on the back; throat reddish; abdomen and crissum white.
Blue of a rich dark purplish shade. Tail about 2.75. Hab. Eastern Province United States, Cuba, and Bermudas … var. sialis.
Blue of a greenish shade. Tail about 3.20. Hab. East Mexico and Guatemala … var. azurea.[26]
2. S. mexicana. Chestnut, in greater or less amount, on the back; throat blue; abdomen and crissum blue. Hab. West and South Middle Province United States, south to Jalapa, Cordova, and Colima.
B. Breast blue (light drab in ♀).
3. S. arctica. Entirely rich greenish-blue; abdomen white. Hab. Middle Province United States; Fort Franklin, British America.