The major tree genera are listed below by taxonomic family.
For classification of flowering plants, see APG II system.
About 210 eudicot families include trees. [1] [2]
About 10 Monocotyledon families include trees. [1] [2]
17 magnoliid families include trees. [1] [2]
7 families, all of them include trees. [3]
Only one species.
2 families include trees. [3]
The gymnosperms are a group of seed-producing plants that includes conifers, cycads, Ginkgo, and gnetophytes, forming the clade Gymnospermae. The term gymnosperm comes from the composite word in Greek: γυμνόσπερμος, literally meaning 'naked seeds'. The name is based on the unenclosed condition of their seeds. The non-encased condition of their seeds contrasts with the seeds and ovules of flowering plants (angiosperms), which are enclosed within an ovary. Gymnosperm seeds develop either on the surface of scales or leaves, which are often modified to form cones, or on their own as in yew, Torreya, Ginkgo. Gymnosperm lifecycles involve alternation of generations. They have a dominant diploid sporophyte phase and a reduced haploid gametophyte phase which is dependent on the sporophytic phase. The term "gymnosperm" is often used in paleobotany to refer to all non-angiosperm seed plants. In that case, to specify the modern monophyletic group of gymnosperms, the term Acrogymnospermae is sometimes used.
Laurel forest, also called laurisilva or laurissilva, is a type of subtropical forest found in areas with high humidity and relatively stable, mild temperatures. The forest is characterized by broadleaf tree species with evergreen, glossy and elongated leaves, known as "laurophyll" or "lauroid". Plants from the laurel family (Lauraceae) may or may not be present, depending on the location.
The Harry P. Leu Gardens are semi-tropical and tropical gardens in Orlando, Florida, United States. The gardens contain nearly 50 acres (200,000 m2) of landscaped grounds and lakes, with trails shaded by 200-year-old oaks and forests of camellias. They are open to the public. The address is 1920 North Forest Avenue Orlando, FL 32803.
The University of Delaware Botanic Gardens are botanical gardens and an arboretum located on the campus of the University of Delaware, in Newark, Delaware, United States. The gardens are open to the public without charge.
The Botanical Garden of the University of Vienna is a botanical garden in Vienna, Austria. It covers 8 hectares and is immediately adjacent to the Belvedere gardens. It is a part of the University of Vienna.
The Donald E. Davis Arboretum, in Auburn, Alabama, United States, is a public native plants museum, and botanical arboretum with educational facilities, event spaces, and a conservation program. Its grounds, covering 13.5 acres of Auburn University's campus, include cataloged living collections of associated tree and plant communities representative of Alabama's ecosystems, among which is mixed oak forest, carnivorous bog, and longleaf pine savanna. The living collections include more than 1,000 plant types, including 500 different plant species, with over 3,000 cataloged specimens. The Arboretum contains over a mile (2 km) of interwoven walking trails that meander through various southeastern biotopes.
The Hilltop Arboretum at Louisiana State University is an arboretum owned by the Louisiana State University. It is located at 11855 Highland Road, Baton Rouge, Louisiana, and open to the public free of charge during daylight hours seven days a week.
The Fell Arboretum is an arboretum located across the campus of Illinois State University in Normal, Illinois.
Klehm Arboretum & Botanic Garden is a nonprofit arboretum and botanical garden located at 2715 South Main Street, Rockford, Illinois.
Nichols Arboretum, locally known as the Arb, is an arboretum on the campus of the University of Michigan, in Ann Arbor, Michigan. The Arb is located adjacent to the Huron River, and features over 400 species, including 110 species of trees, in a varied, hilly landscape. A signature feature of Nichols Arboretum is the W. E. Upjohn Peony Garden, which features the largest collection of heirloom peonies in North America.
Verticillium wilt is a wilt disease affecting over 350 species of eudicot plants. It is caused by six species of Verticillium fungi: V. dahliae, V. albo-atrum, V. longisporum, V. nubilum, V. theobromae and V. tricorpus. Many economically important plants are susceptible including cotton, tomatoes, potatoes, oilseed rape, eggplants, peppers and ornamentals, as well as others in natural vegetation communities. Many eudicot species and cultivars are resistant to the disease and all monocots, gymnosperms and ferns are immune.
Regional floras typically contain complete dichotomous keys for identification of trees and other plants to species. The following guide originates from Our Native Trees and How to Identify Them by Harriet L. Keeler and applies to some flowering trees which are indigenous to the region extending from the Atlantic Ocean to the Rocky Mountains and from Canada to the northern boundaries of the southern states, together with a few well-known and naturalized foreign trees. This guide excludes conifers and is not an exhaustive list of all trees known to occur in the region.
A list of prehistoric and extant species whose fossils have been found in the London Clay, which underlies large areas of southeast England.