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Tree
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only plants that are usable as lumber, or only plants above a specified height. But wider definitions include taller palms, tree ferns, bananas, and bamboos. Trees are not a monophyletic taxonomic group but consist of a wide variety of plant species that have independently evolved a trunk and branches as a way to tower above other plants to compete for sunlight. The majority of tree species are angiosperms or hardwoods; of the rest, many are gymnosperms or softwoods. Trees tend to be long-lived, some trees reaching several thousand years old. Trees evolved around 400 million years ago, and it is estimated that there are around three trillion mature trees in the world currently. A tree typically has many secondary branches supported cle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trunk (botany)
Trunks are the Plant stem, stems of woody plants and the main structural element of trees. The woody part of the trunk consists of dead but structurally significant heartwood and living sapwood, which is used for nutrient storage and transport. Separating the wood from the bark is the Vascular cambium, cambium, from which trunks grow in diameter. Bark is divided between the living inner bark (the phloem), which transports sugars, and the outer bark, which is a dead protective layer. The precise Cell (biology), cellular makeup of these components differs between non-flowering plants (gymnosperms) and flowering plants (Flowering plant, angiosperms). A variety of specialised cells facilitate the storage of carbohydrates, water, minerals, and transport of water, minerals, and hormones around the plant. Growth is achieved by Cell division, division of these cells. Vertical growth is generated from the Meristem, apical meristems (stem tips), and horizontal (radial) growth, from the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arecaceae
The Arecaceae () is a family (biology), family of perennial plant, perennial, flowering plants in the Monocotyledon, monocot order Arecales. Their growth form can be climbing palm, climbers, shrubs, tree-like and stemless plants, all commonly known as palms. Those having a tree-like form are colloquially called palm trees. Currently, 181 Genus, genera with around 2,600 species are known, most of which are restricted to tropics, tropical and subtropics, subtropical climates. Most palms are distinguished by their large, compound, evergreen leaves, known as fronds, arranged at the top of an unbranched stem, except for the Hyphaene genus, who has branched palms. However, palms exhibit an enormous diversity in physical characteristics and inhabit nearly every type of Habitat (ecology), habitat within their range, from rainforests to deserts. Palms are among the best known and most extensively Horticulture, cultivated plant families. They have been important to humans throughout much ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyatheales
The order Cyatheales, which includes most tree ferns, is a Taxonomy (biology), taxonomic order of the fern class, Polypodiopsida. No clear morphology (biology), morphological features characterize all of the Cyatheales, but DNA sequence data indicate the order is monophyly, monophyletic. Some species in the Cyatheales have tree-like growth forms from a vertical rhizome, others have shorter or horizontal expanding rhizomes. Some species have scales on the stems and leaves, while others have hairs. However, most plants in the Cyatheales are tree ferns and have trunk-like stems up to tall. It is unclear how many times the tree form has evolved and been lost in the order.Judd, W.S., C.S. Campbell, E.A. Kellogg, P.F. Stevens, and M.J. Donoghue (Eds.) 2008. Plant Systematics: A Phylogenetic Approach, Third Edition. Sinauer Associates, Sunderland, Massachusetts, USA. Description While the Cyatheales have been shown to be monophyletic through molecular analysis, no prominent morphologic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bark (botany)
Bark is the outermost layer of Plant stem, stems and roots of woody plants. Plants with bark include trees, woody vines, and shrubs. Bark refers to all the Tissue (biology), tissues outside the vascular cambium and is a nontechnical term. It overlays the wood and consists of the inner bark and the outer bark. The inner bark, which in older Plant stem, stems is living tissue, includes the innermost layer of the periderm. The outer bark on older stems includes the dead tissue on the surface of the stems, along with parts of the outermost periderm and all the tissues on the outer side of the periderm. The outer bark on trees which lies external to the living periderm is also called the Glossary of botanical terms#rhytidome, rhytidome. Products derived from bark include bark shingle siding and wall coverings, spices, and other flavorings, tanbark for tannin, resin, latex, medicines, poisons, various hallucinogenic chemicals, and Cork (material), cork. Bark has been used to make clot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angiosperm
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed within a fruit. The group was formerly called Magnoliophyta. Angiosperms are by far the most diverse group of land plants with 64 orders, 416 families, approximately 13,000 known genera and 300,000 known species. They include all forbs (flowering plants without a woody stem), grasses and grass-like plants, a vast majority of broad-leaved trees, shrubs and vines, and most aquatic plants. Angiosperms are distinguished from the other major seed plant clade, the gymnosperms, by having flowers, xylem consisting of vessel elements instead of tracheids, endosperm within their seeds, and fruits that completely envelop the seeds. The ancestors of flowering plants diverged from the common ancestor of all living gymnosperms before the end of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Stem
A stem is one of two main structural axes of a vascular plant, the other being the root. It supports leaf, leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and phloem, engages in photosynthesis, stores nutrients, and produces new living tissue. The stem can also be called the culm, halm, haulm, stalk, or thyrsus. The stem is normally divided into nodes and internodes: * The nodes are the points of attachment for leaves and can hold one or more leaves. There are sometimes axillary buds between the stem and leaf which can grow into branches (with leaf, leaves, conifer cones, or inflorescence, flowers). Adventitious roots (e.g. brace roots) may also be produced from the nodes. Vines may produce tendrils from nodes. * The internodes distance one node from another. The term "Shoot (botany), shoots" is often confused with "stems"; "shoots" generally refers to new fresh plant growth, including both stems and other str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Branch
A branch, also called a ramus in botany, is a stem that grows off from another stem, or when structures like veins in leaves are divided into smaller veins. History and etymology In Old English, there are numerous words for branch, including , , , and . There are also numerous descriptive words, such as (that is, something that has bled, or 'bloomed', out), (literally 'little bough'), (literally 'on growth'), and (literally 'offspringing'). Numerous other words for twigs and boughs abound, including , which still survives as the ''-toe'' in ''mistletoe''. Latin words for branch are or . The latter term is an affix found in other modern words such as '' cladodont'' (prehistoric sharks with branched teeth), ''cladode'' (flattened leaf-like branches), or ''cladogram'' (a branched diagram showing relations among organisms). Woody branches Large branches are known as boughs and small branches are known as twigs. The term ''twig'' usually refers to a terminus, while ''bou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monophyletic Group
In biology, a clade (), also known as a monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach to taxonomy adopted by most biological fields. The common ancestor may be an individual, a population, or a species (extinct or extant). Clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently. Clades are termed ''monophyletic'' (Greek: "one clan") groups. Over the last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming taxa that are not clades; that is, taxa that are not monophyletic. Some of the relationships between organisms that the molecular biology arm of cladistics has revealed i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Larix Decidua Aletschwald
Larches are deciduous conifers in the genus ''Larix'', of the family Pinaceae (subfamily Laricoideae). Growing from tall, they are native to the cooler regions of the northern hemisphere, where they are found in lowland forests in the high latitudes, and high in mountains further south. Larches are among the dominant plants in the boreal forests of Siberia and Canada. Although they are conifers, larches are deciduous trees that lose their needles in the autumn. Description and distribution The tallest species, '' Larix occidentalis'', can reach . Larch tree crowns are sparse, with the major branches horizontal; the second and third order branchlets are also ± horizontal in some species (e.g. '' L. gmelinii'', '' L. kaempferi''), or characteristically pendulous in some other species (e.g. '' L. decidua'', '' L. griffithii''). Larch shoots are dimorphic, with leaves borne singly on long shoots typically long and bearing several buds, and in dense clusters of 20–50 need ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spore
In biology, a spore is a unit of sexual reproduction, sexual (in fungi) or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the Biological life cycle, life cycles of many plants, algae, fungus, fungi and protozoa. They were thought to have appeared as early as the mid-late Ordovician period as an adaptation of early land plants. Bacterial spores are not part of a sexual cycle, but are resistant structures used for survival under unfavourable conditions. Myxozoan spores release amoeboid infectious germs ("amoebulae") into their hosts for parasitic infection, but also reproduce within the hosts through the pairing of two nuclei within the plasmodium, which develops from the amoebula. In plants, spores are usually haploid and unicellular and are produced by meiosis in the sporangium of a diploid sporophyte. In some rare cases, a diploid spore is also p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leaves
A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, flower, and fruit collectively form the shoot system. In most leaves, the primary photosynthetic tissue is the palisade mesophyll and is located on the upper side of the blade or lamina of the leaf, but in some species, including the mature foliage of ''Eucalyptus'', palisade mesophyll is present on both sides and the leaves are said to be isobilateral. The leaf is an integral part of the stem system, and most leaves are flattened and have distinct upper ( adaxial) and lower ( abaxial) surfaces that differ in color, hairiness, the number of stomata (pores that intake and output gases), the amount and structure of epicuticular wax, and other features. Leaves are mostly green in color due to the presence of a compound called chlorop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Growth
In botany, secondary growth is the growth that results from cell division in the cambia or lateral meristems and that causes the stems and roots to thicken, while primary growth is growth that occurs as a result of cell division at the tips of stems and roots, causing them to elongate, and gives rise to primary tissue. Secondary growth occurs in most seed plants, but monocots usually lack secondary growth. If they do have secondary growth, it differs from the typical pattern of other seed plants. The formation of secondary vascular tissues from the cambium is a characteristic feature of dicotyledons and gymnosperms. In certain monocots, the vascular tissues are also increased after the primary growth is completed but the cambium of these plants is of a different nature. In the living pteridophytes this feature is extremely rare, only occurring in '' Isoetes''. Lateral meristems In many vascular plants, secondary growth is the result of the activity of the two lateral me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
