USS "Egeria" (ARL-8) was one of 39 "Achelous"-class landing craft repair ships built for the United States Navy during World War II.
 Named for Egeria (a fountain nymph in Roman mythology, and the wife of Numa Pompilius), she was the only U.S. Naval vessel to bear the name.
13 Egeria is a large main-belt G-type asteroid.
 It was discovered by Annibale de Gasparis on November 2, 1850.
 Egeria was named by Urbain Le Verrier, whose computations led to the discovery of Neptune, after the mythological nymph Egeria of Aricia, Italy, the wife of Numa Pompilius, second king of Rome.
Azorella selago is a species of cushion plant native to the sub-Antarctic islands of the Southern Ocean, including the Crozet Islands, the Possession Islands, the Heard Island and McDonald Islands, the Kerguelen Islands, and the Prince Edward Islands.
 The closely related "Azorella macquariensis", which is endemic to Macquarie Island, was split from it taxonomically in 1989.
 "A. selago" is often a keystone species where it occurs and is well studied for its contribution to its native ecosystems.
Three Royal Navy ships have been called HMS "Egeria":
Egeria is a genus of three species of aquatic plants in the family Hydrocharitaceae described as a genus in 1849.
 native to warm-temperate South America.
Huperzia selago, the northern firmoss or fir clubmoss, is a vascular plant in the family Lycopodiaceae.
 It has a circumpolar distribution in temperate and boreal regions in both hemispheres.
 In the past, this species has also been named "Lycopodium selago".
Egeria is an unincorporated community in Mercer and Raleigh counties, West Virginia, United States.
 Egeria is 8.5 mi north-northeast of Matoaka.
Egeria densa, the large-flowered waterweed or Brazilian waterweed, is a species of "Egeria" native to warm temperate South America in southeastern Brazil, Argentina, and Uruguay.
 It is considered a problematic invasive species due to its use in home aquariums and subsequent release into non-native habitats.
HMS "Egeria" was a 4-gun screw sloop of the "Fantome" class launched at Pembroke on 1 November 1873.
 She was named after Egeria, a water nymph of Roman mythology, and was the second ship of the Royal Navy to bear the name.
 After a busy career in the East Indies, Pacific, Australia and Canada, she was sold for breaking in 1914 and was burnt at Burrard Inlet in British Columbia.
Selago is a genus of plant in family Scrophulariaceae, closely related to "Scrophularia" and "Verbascum".
 It contains around 190 species, mostly in southern Africa; two are listed on the IUCN Red List:

Question: What are both Egeria and Selago?
Answer: a genus of plant