Acotyledon is used to refer to seed plants or spermatophytes that lack cotyledons, such as orchids and dodder. Orchid seeds are tiny with underdeveloped embryos. They depend on mycorrhizal fungi for their early nutrition so are myco-heterotrophs at that stage.[ citation needed ]
Although some authors, especially in the 19th century and earlier, use the word acotyledon to include plants which have no cotyledons because they lack seeds entirely (such as ferns and mosses), [1] [2] [3] others restrict the term to plants which have seeds but no cotyledons. [4]
Flowering plants or angiosperms are divided into two large groups. Monocotyledons or monocots have one seed lobe, which is often modified to absorb stored nutrients from the seed so never emerges from the seed or becomes photosynthetic. Dicotyledons or dicots have two cotyledons and often germinate to produce two leaf-like cotyledons. Conifers and other gymnosperms lack flowers but may have two or more cotyledons in the seedling.[ citation needed ]
Orchids are plants that belong to the family Orchidaceae, a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant.
In botany, a seed is a plant embryo and food reserve enclosed in a protective outer covering called a seed coat (testa). More generally, the term "seed" means anything that can be sown, which may include seed and husk or tuber. Seeds are the product of the ripened ovule, after the embryo sac is fertilized by sperm from pollen, forming a zygote. The embryo within a seed develops from the zygote and grows within the mother plant to a certain size before growth is halted.
A cotyledon is a significant part of the embryo within the seed of a plant, and is defined as "the embryonic leaf in seed-bearing plants, one or more of which are the first to appear from a germinating seed." The number of cotyledons present is one characteristic used by botanists to classify the flowering plants (angiosperms). Species with one cotyledon are called monocotyledonous ("monocots"). Plants with two embryonic leaves are termed dicotyledonous ("dicots").
Monocotyledons, commonly referred to as monocots, are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one embryonic leaf, or cotyledon. They constitute one of the major groups into which the flowering plants have traditionally been divided; the rest of the flowering plants have two cotyledons and are classified as dicotyledons, or dicots.
Germination is the process by which an organism grows from a seed or spore. The term is applied to the sprouting of a seedling from a seed of an angiosperm or gymnosperm, the growth of a sporeling from a spore, such as the spores of fungi, ferns, bacteria, and the growth of the pollen tube from the pollen grain of a seed plant.
The hypocotyl is the stem of a germinating seedling, found below the cotyledons and above the radicle (root).
Hypogeal, hypogean, hypogeic and hypogeous are biological terms describing an organism's activity below the soil surface.
Gesneriaceae, the gesneriad family, is a family of flowering plants consisting of about 152 genera and ca. 3,540 species in the tropics and subtropics of the Old World and the New World, with a very small number extending to temperate areas. Many species have colorful and showy flowers and are cultivated as ornamental plants.
The endosperm is a tissue produced inside the seeds of most of the flowering plants following double fertilization. It is triploid in most species, which may be auxin-driven. It surrounds the embryo and provides nutrition in the form of starch, though it can also contain oils and protein. This can make endosperm a source of nutrition in animal diet. For example, wheat endosperm is ground into flour for bread, while barley endosperm is the main source of sugars for beer production. Other examples of endosperm that forms the bulk of the edible portion are coconut "meat" and coconut "water", and corn. Some plants, such as orchids, lack endosperm in their seeds.
Bauhinia × blakeana, commonly called the Hong Kong orchid tree, is a hybrid leguminous tree of the genus Bauhinia. It has large thick leaves and striking purplish red flowers. The fragrant, orchid-like flowers are usually 10 to 15 centimetres across, and bloom from early November to the end of March. Although now cultivated in many areas, it originated in Hong Kong in 1880 and apparently all of the cultivated trees derive from one cultivated at the Hong Kong Botanical Gardens and widely planted in Hong Kong starting in 1914. It is referred to as bauhinia in non-scientific literature though this is the name of the genus. It is sometimes called the Hong Kong orchid. In Hong Kong, it is most commonly referred to by its Chinese name of 洋紫荊 (yèuhng jígīng).
Potpourri is a mixture of dried, naturally fragrant plant materials used to provide a gentle natural scent, commonly in residential settings. It is often placed in a decorative bowl.
The ground tissue of plants includes all tissues that are neither dermal nor vascular. It can be divided into three types based on the nature of the cell walls.
A seedling is a young sporophyte developing out of a plant embryo from a seed. Seedling development starts with germination of the seed. A typical young seedling consists of three main parts: the radicle, the hypocotyl, and the cotyledons. The two classes of flowering plants (angiosperms) are distinguished by their numbers of seed leaves: monocotyledons (monocots) have one blade-shaped cotyledon, whereas dicotyledons (dicots) possess two round cotyledons. Gymnosperms are more varied. For example, pine seedlings have up to eight cotyledons. The seedlings of some flowering plants have no cotyledons at all. These are said to be acotyledons.
Plant taxonomy is the science that finds, identifies, describes, classifies, and names plants. It is one of the main branches of taxonomy.
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants. Flowers produce gametophytes, which in flowering plants consist of a few haploid cells which produce gametes. The "male" gametophyte, which produces non-motile sperm, is enclosed within pollen grains; the "female" gametophyte is contained within the ovule. When pollen from the anther of a flower is deposited on the stigma, this is called pollination. Some flowers may self-pollinate, producing seed using pollen from the same flower or a different flower of the same plant, but others have mechanisms to prevent self-pollination and rely on cross-pollination, when pollen is transferred from the anther of one flower to the stigma of another flower on a different individual of the same species.
In natural science, subaerial has been used since 1833, notably in geology and botany, to describe features and events occurring or formed on or near the Earth's land surface. They are thus exposed to Earth's atmosphere. This may be contrasted with subaqueous events or features located below a water surface, submarine events or features located below a sea surface, subterranean events or features located below ground, or subglacial events or features located below glacial ice such as ice sheets.
Microgreens are vegetable greens harvested just after the cotyledon leaves have developed with one set of true leaves. They are used as a visual, flavor and texture enhancement. Microgreens are used to add sweetness and spiciness to foods. Microgreens are smaller than “baby greens” because they are harvested soon after sprouting, rather than after the plant has matured to produce multiple leaves.
In plant morphology, a cataphyll is a reduced, small leaf. Many plants have both "true leaves" (euphylls), which perform most of the photosynthesis, and cataphylls, which are modified to perform other functions.
Hypogeal germination is a botanical term indicating that the germination of a plant takes place below the ground. An example of a plant with hypogeal germination is the pea. The opposite of hypogeal is epigeal.
The monocots are one of the two major groups of flowering plants, the other being the dicots. In order to reproduce they utilize various strategies such as employing forms of asexual reproduction, restricting which individuals they are sexually compatible with, or influencing how they are pollinated. Nearly all reproductive strategies that evolved in the dicots have independently evolved in monocots as well. Despite these similarities and their close relatedness, monocots and dicots have distinct traits in their reproductive biologies.