Alders are trees comprising the genus Alnus in the birch family Betulaceae. The genus comprises about 35 species of monoecious trees and shrubs, a few reaching a large size, distributed throughout the north temperate zone with a few species extending into Central America, as well as the northern and southern Andes.
Betulaceae, the birch family, includes six genera of deciduous nut-bearing trees and shrubs, including the birches, alders, hazels, hornbeams, hazel-hornbeam, and hop-hornbeams numbering a total of 167 species. They are mostly natives of the temperate Northern Hemisphere, with a few species reaching the Southern Hemisphere in the Andes in South America. Their typical flowers are catkins and often appear before leaves.
Alnus glutinosa, the common alder, black alder, European alder, European black alder, or just alder, is a species of tree in the family Betulaceae, native to most of Europe, southwest Asia and northern Africa. It thrives in wet locations where its association with the bacterium Frankia alni enables it to grow in poor quality soils. It is a medium-sized, short-lived tree growing to a height of up to 30 metres (98 feet). It has short-stalked rounded leaves and separate male and female flowers in the form of catkins. The small, rounded fruits are cone-like and the seeds are dispersed by wind and water.
Alnus rubra, the red alder, is a deciduous broadleaf tree native to western North America.
Alnus incana, the grey alder or speckled alder, is a species of multi-stemmed, shrubby tree in the birch family, with a wide range across the cooler parts of the Northern Hemisphere. Tolerant of wetter soils, it can slowly spread with runners and is a common sight in swamps and wetlands. It is easily distinguished by its small cones, speckled bark and broad leaves.
Alnus jorullensis, commonly known as Mexican alder, is an evergreen or semi-evergreen alder, native to eastern and southern Mexico, Guatemala and Honduras. Although previously reported from the Andes, further collections showed these to be the similar species Alnus acuminata, commonly found in South America.
Alnus cordata, the Italian alder, is a tree or shrub species belonging to the family Betulaceae, and native to the southern Apennine Mountains and the north-eastern mountains of Corsica. It has been introduced in Sicily, Sardinia, and more recently in Central-Northern Italy, other European countries and extra-European countries, where it has become naturalised.
Alnus subcordata, the Caucasian alder, is a species in the family Betulaceae, native to Hyrcanian forests of Iran and the Caucasus. It is closely related to the Italian alder and Alnus orientalis.
Betula nana, the dwarf birch, is a species of birch in the family Betulaceae, found mainly in the tundra of the Arctic region.
Armeria maritima, the thrift, sea thrift or sea pink, is a species of flowering plant in the family Plumbaginaceae. It is a compact evergreen perennial which grows in low clumps and sends up long stems that support globes of bright pink flowers. In some cases purple, white or red flowers also occur. It is a popular garden flower and has been distributed worldwide as a garden and cut flower. It does well in gardens designed as xeriscapes or rock gardens. The Latin specific epithet maritima means pertaining to the sea or coastal.
Banksia borealis is a species of sprawling shrub that is endemic to Western Australia. It has leaves with sharply pointed lobes on each side, between thirty and fifty flowers in a gold-coloured spike and egg-shaped fruit. There are two subspecies occurring in two disjunct areas.
Portencross is a hamlet near Farland Head in North Ayrshire, Scotland. Situated about three kilometres west of Seamill and about two kilometres south of Hunterston B nuclear power station, it is noted for Portencross Castle.
Eucalyptus macrorhyncha, commonly known as the red stringybark, is a species of medium-sized tree that is endemic to eastern Australia. It has rough, stringy, grey to brown bark, lance-shaped adult leaves, flower buds in groups of between seven and eleven, white flowers and hemispherical fruit.
Plantago maritima, the sea plantain, seaside plantain or goose tongue, is a species of flowering plant in the plantain family Plantaginaceae. It has a subcosmopolitan distribution in temperate and Arctic regions, native to most of Europe, northwest Africa, northern and central Asia, northern North America, and southern South America.
Alnus acuminata is a species of deciduous tree in the Betulaceae family. It is found in montane forests from central Mexico to Argentina.
Oenothera macrocarpa, the bigfruit evening primrose, Ozark sundrops, Missouri evening primrose, or Missouri primrose, is a species of flowering plant in the evening primrose family Onagraceae, native to northeast Mexico and the south-central United States, where it is found in calcareous prairies and limestone outcrops.
Alnus serrulata, the hazel alder or smooth alder, is a thicket-forming shrub in the family Betulaceae. It is native to eastern North America and can be found from western Nova Scotia and southern New Brunswick south to Florida and Texas.
Alnus alnobetula is a common tree widespread across much of Europe, Asia, and North America. Many sources refer to it as Alnus viridis, the green alder, but botanically this is considered an illegitimate name synonymous with Alnus alnobetula subsp. fruticosa.
Cistus chinamadensis is a shrubby species of flowering plant in the family Cistaceae, with purple-pink flowers, first described in 1991. It is endemic to the Canary Islands, where three subspecies occur on three separate islands. The species has been assessed as endangered in the IUCN Red List, being known only from small separated areas and facing a variety of threats.
Caladenia caesarea subsp. maritima, commonly known as the cape spider orchid, is a plant in the orchid family Orchidaceae and is endemic to the south-west of Western Australia. It has a single spreading, hairy leaf and up to three small mustard-coloured flowers with red stripes. It is only known from a small coastal area near Cape Leeuwin where it grows in clumps of ten or more.
