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Catkins
A catkin or ament is a slim, cylindrical flower cluster (a spike), with inconspicuous or no petals, usually wind-pollinated (anemophilous) but sometimes insect-pollinated (as in ''Salix''). It contains many, usually unisexual flowers, arranged closely along a central stem that is often drooping. Catkins are found in many plant families, including Betulaceae, Fagaceae, Moraceae, and Salicaceae. Occurrence Catkin-bearing plants include many trees or shrubs such as birch, willow, aspen, hickory, sweet chestnut, and sweetfern (''Comptonia''). In many of these plants, only the male flowers form catkins, and the female flowers are single (hazel, oak), a cone (alder), or other types (mulberry). '' Corylus jacquemontii'' has male catkins and also female spikes. In other plants (such as poplar), both male and female flowers are borne in catkins. ''Populus alba'' has male catkins which are grey and the female catkins are greyish-green. While the blooming months for catkins may vary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alder
Alders are trees of the genus ''Alnus'' in the birch family Betulaceae. The genus includes 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. Description With a few exceptions, alders are deciduous, and the leaves are alternate, simple, and serrated. The flowers are catkins with elongate male catkins on the same plant as shorter female catkins, often before leaves appear; they are mainly wind-pollinated, but also visited by bees to a small extent. These trees differ from the birches (''Betula'', another genus in the family) in that the female catkins are woody and do not disintegrate at maturity, opening to release the seeds in a similar manner to many conifer cones. The largest species are red alder (''A. rubra'') on the west coast of North America, and black alder (''A. glutinosa''), native to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Populus Alba
''Populus alba'', commonly called silver poplar,Webb, C. J.; Sykes, W. R.; Garnock-Jones, P. J. 1988: Flora of New Zealand. Vol. IV. Naturalised Pteridophytes, Gymnosperms, Dicotyledons. 4. Christchurch, New Zealand, Botany Division, D.S.I.R. silverleaf poplar, white poplar, or abele is a species of Populus, poplar, most closely related to the aspens (''Populus'' sect. ''Populus''). It is native to a region spanning from the Atlas Mountains of Africa, through most of South and Central Europe, into Central Asia; it has been introduced to many temperate, moist regions worldwide. It grows in moist sites, often by watersides, in regions with hot summers and cold to mild winters.Flora Europaea''Populus alba''/ref>Rushforth, K. (1999). ''Trees of Britain and Europe''. Collins . Description It is a medium-sized deciduous tree, growing to heights of up to (rarely more), with a trunk up to in diameter and a broad, rounded crown. The Bark (botany), bark is smooth and greenish-white to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birch
A birch is a thin-leaved deciduous hardwood tree of the genus ''Betula'' (), in the family Betulaceae, which also includes alders, hazels, and hornbeams. It is closely related to the beech- oak family Fagaceae. The genus ''Betula'' contains 30 to 60 known taxa of which 11 are on the IUCN 2011 Red List of Threatened Species. They are typically short-lived pioneer species and are widespread in the Northern Hemisphere, particularly in northern areas of temperate climates and in boreal climates. Birch wood is used for a wide range of purposes. Description Birch species are generally small to medium-sized trees or shrubs, mostly of northern temperate and boreal climates. The simple leaves are alternate, singly or doubly serrate, feather-veined, petiolate and stipulate. They often appear in pairs, but these pairs are really borne on spur-like, two-leaved, lateral branchlets. The fruit is a small samara, although the wings may be obscure in some species. They differ from t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hazel
Hazels are plants of the genus ''Corylus'' of deciduous trees and large shrubs native to the temperate Northern Hemisphere. The genus is usually placed in the birch family, Betulaceae,Germplasmgobills Information Network''Corylus''Rushforth, K. (1999). ''Trees of Britain and Europe''. Collins .Huxley, A., ed. (1992). ''New RHS Dictionary of Gardening''. Macmillan . though some botanists split the hazels (with the hornbeams and allied genera) into a separate family Corylaceae. The fruit of the hazel is the hazelnut. Hazels have simple, rounded leaves with double-serrate margins. The flowers are produced very early in spring before the leaves, and are monoecious, with single-sex catkins. The male catkins are pale yellow and long, and the female ones are very small and largely concealed in the buds, with only the bright-red, 1-to-3 mm-long styles visible. The fruits are nuts long and 1–2 cm diameter, surrounded by an involucre (husk) which partly to fully encloses ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chestnut
The chestnuts are the deciduous trees and shrubs in the genus ''Castanea'', in the beech family Fagaceae. The name also refers to the edible nuts they produce. They are native to temperate regions of the Northern Hemisphere. Description Chestnut trees are of moderate growth rate (for the Chinese chestnut tree) to fast-growing for American and European species. Their mature heights vary from the smallest species of chinkapins, often shrubby,''Chestnuts, Horse-Chestnuts, and Ohio Buckeyes'' . In Yard and Garden Brief, Horticulture department at University of Minnesota. to the giant of past American forests, '' C. dentata'' that could reach . Between these extremes ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Sexuality
Plant reproductive morphology is the study of the physical form and structure (the morphology) of those parts of plants directly or indirectly concerned with sexual reproduction. Among all living organisms, flowers, which are the reproductive structures of angiosperms, are the most varied physically and show a correspondingly great diversity in methods of reproduction. Plants that are not flowering plants ( green algae, mosses, liverworts, hornworts, ferns and gymnosperms such as conifers) also have complex interplays between morphological adaptation and environmental factors in their sexual reproduction. The breeding system, or how the sperm from one plant fertilizes the ovum of another, depends on the reproductive morphology, and is the single most important determinant of the genetic structure of nonclonal plant populations. Christian Konrad Sprengel (1793) studied the reproduction of flowering plants and for the first time it was understood that the pollination pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Betulaceae
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. In the past, the family was often divided into two families, Betulaceae (''Alnus'', ''Betula'') and Corylaceae (the rest). Recent treatments, including the Angiosperm Phylogeny Group, have described these two groups as subfamilies within an expanded Betulaceae: Betuloideae and Coryloideae. Betulaceae flowers are monoecious, meaning that they have both male and female flowers on the same tree. Their flowers present as catkins and are small and inconspicuous, often with reduced perianth parts. These flowers have large feathery stamen and produce a high vo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Populus
''Populus'' is a genus of 25–30 species of deciduous flowering plants in the family Salicaceae, native to most of the Northern Hemisphere. English names variously applied to different species include poplar (), aspen, and cottonwood. The western balsam poplar (Populus trichocarpa, ''P. trichocarpa'') was the first tree to have its full DNA code determined by DNA sequencing, in 2006. Description The genus has a large genetic diversity, and can grow from tall, with trunks up to in diameter. The Bark (botany), bark on young trees is smooth and white to greenish or dark gray, and often has conspicuous lenticels; on old trees, it remains smooth in some species, but becomes rough and deeply fissured in others. The shoots are stout, with (unlike in the related willows) the terminal bud present. The leaves are spirally arranged, and vary in shape from triangular to circular or (rarely) lobed, and with a long petiole (botany), petiole; in species in the sections ''Populus'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Willow
Willows, also called sallows and osiers, of the genus ''Salix'', comprise around 350 species (plus numerous hybrids) of typically deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions. Most species are known as willow, but some narrow-leaved shrub species are called osier, and some broader-leaved species are referred to as sallow (from Old English ''sealh'', related to the Latin word ''salix'', willow). Some willows (particularly arctic and alpine species) are low-growing or creeping shrubs; for example, the dwarf willow (''Salix herbacea'') rarely exceeds in height, though it spreads widely across the ground. Description Willows all have abundant watery bark sap, which is heavily charged with salicin, soft, usually pliant, tough wood, slender branches, and large, fibrous, often stoloniferous roots. The roots are remarkable for their toughness, size, and tenacity to live, and roots readily sprout from aerial parts of the plant. Lea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hamamelididae
Hamamelididae is an obsolete botanical name at the rank of subclass. Because some hamamelidid members bear aments (''i.e.'', catkins), this subclass has been formerly known as ''Amentiferae''. Based on molecular phylogeny works, Hamamelididae appears to be a polyphyletic group.Savolainen, V., M. W. Chase, S. B. Hoot, C. M. Morton, D. E. Soltis, C. Bayer, M. F. Fay, A. Y. De Bruijn, S. Sullivan, and Y.-L. Qiu. 2000. Phylogenetics of flowering plants based on combined analysis of plastid ''atpB'' and ''rbcL'' gene sequences. ''Systematic Biology'' 49:306-362. Soltis, D. E. et alii. (28 authors). 2011. "Angiosperm phylogeny: 17 genes, 640 taxa". ''American Journal of Botany'' 98(4):704-730. A well-known system that used the name Hamamelididae is the Cronquist system, although in the disallowed spelling ''Hamamelidae''. In the original 1981 version of this system the circumscription was: * subclass Hamamelidae *: order Trochodendrales *: order Hamamelidales *: order Daphniphyll ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
