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, Botanical Terms - Acetabularia
often known as the mermaid's wineglass or cup
a genus of *dasycladalean algae where the mature *thallus is made up of a whorl of *gametangial sacs at the summit of a single *axis, or "stalk." Found affixed to rocks, shells, and other objects in shallow, protected waters in warm climates. There are fossilized Acetabularia from the *Tertiary period.
often known as the mermaid's wineglass or cup
a genus of *dasycladalean algae where the mature *thallus is made up of a whorl of *gametangial sacs at the summit of a single *axis, or "stalk." Found affixed to rocks, shells, and other objects in shallow, protected waters in warm climates. There are fossilized Acetabularia from the *Tertiary period.
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Botanical Terms - Acalypha (Euphorbiaceae family)
A genus of *small trees and shrubs with unisexual, apetalous blooms; males have long, twisted *anther-lobes, while females have many-branched stigmas (see CARPEL); some species have *catkins (such as the decorative A. hispida, or "cat's tail"). The foliage of A. wilkesiana and other plants is colorful. The family bears merely a passing similarity to *Urticaceae; there are no near cousins. Found in the tropics and subtropics, there are between 450 and 62 species.
A genus of *small trees and shrubs with unisexual, apetalous blooms; males have long, twisted *anther-lobes, while females have many-branched stigmas (see CARPEL); some species have *catkins (such as the decorative A. hispida, or "cat's tail"). The foliage of A. wilkesiana and other plants is colorful. The family bears merely a passing similarity to *Urticaceae; there are no near cousins. Found in the tropics and subtropics, there are between 450 and 62 species.
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Botanical Terms - accumulated temperature
the total, expressed in degrees, by which the real air temperature fluctuates over an extended period of time above or below a datum level. Typically, the datum level is established at a temperature that is pertinent to agricultural production or ecological research (for example, 6°C is the essential temperature for sustained plant growth). The accumulated temperature for a given day is mn/24 degree-days if the mean temperature is m° above or below (−m°) the datum level and stays there for n hours (= n/24 days). To find the total temperature over a week, month, season, or year, simply add the degree-days.
the total, expressed in degrees, by which the real air temperature fluctuates over an extended period of time above or below a datum level. Typically, the datum level is established at a temperature that is pertinent to agricultural production or ecological research (for example, 6°C is the essential temperature for sustained plant growth). The accumulated temperature for a given day is mn/24 degree-days if the mean temperature is m° above or below (−m°) the datum level and stays there for n hours (= n/24 days). To find the total temperature over a week, month, season, or year, simply add the degree-days.
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Botanical Terms -absolute pollen frequency (APF)
The expression of *pollen data from sediments in terms of the absolute numbers (for each species, genus, or family) per unit area of surface and, where deposition rates are known, per unit time. This method provides more precise information in some situations than the conventional expression as *relative pollen frequencies (RPFs). When comparing sites that differ in one or more high-pollen producers, APFs are especially helpful. For instance, an RPF method's copious pollen may indicate a decline in herbaceous species when trees first arrive in the area pollen rain, but an APF method's analysis will reveal consistent values for herb species.
The expression of *pollen data from sediments in terms of the absolute numbers (for each species, genus, or family) per unit area of surface and, where deposition rates are known, per unit time. This method provides more precise information in some situations than the conventional expression as *relative pollen frequencies (RPFs). When comparing sites that differ in one or more high-pollen producers, APFs are especially helpful. For instance, an RPF method's copious pollen may indicate a decline in herbaceous species when trees first arrive in the area pollen rain, but an APF method's analysis will reveal consistent values for herb species.
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Botanical Terms -Absorption
the process by which cells or tissues absorb things, most commonly nutrition, water, or light.
the process by which cells or tissues absorb things, most commonly nutrition, water, or light.
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Botanical Terms -absorption spectrum
a graph that displays the proportion of each wavelength of light that a pigment, such as chlorophyll, which mostly absorbs in the red and blue regions of the spectrum, absorbs.
a graph that displays the proportion of each wavelength of light that a pigment, such as chlorophyll, which mostly absorbs in the red and blue regions of the spectrum, absorbs.
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Botanical Terms -Abutilon (Malvaceae family)
A genus of trees and shrubs with hairy leaves and branches that are native to mild temperate and tropical regions, and vivid, lantern-like blooms that are mostly orange or red. The *stigmas are often *apical, and the fruit is a *schizocarp. Approximately 200 species exist. One member of the genus is A. theophrasti, or China jute
A genus of trees and shrubs with hairy leaves and branches that are native to mild temperate and tropical regions, and vivid, lantern-like blooms that are mostly orange or red. The *stigmas are often *apical, and the fruit is a *schizocarp. Approximately 200 species exist. One member of the genus is A. theophrasti, or China jute
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Botanical Terms - Acacia
Mostly found in temperate and subtropical locations, Acaena is a genus of wind-pollinated, mat-forming plants (family *Rosaceae, subfamily Rosoideae, *tribe Sanguisorbeae). There are roughly 100 species total; 90 of them are known to exist in South America, 14 in New Zealand, 2 in Australia, and more species in South Africa, California, and New Guinea.
Mostly found in temperate and subtropical locations, Acaena is a genus of wind-pollinated, mat-forming plants (family *Rosaceae, subfamily Rosoideae, *tribe Sanguisorbeae). There are roughly 100 species total; 90 of them are known to exist in South America, 14 in New Zealand, 2 in Australia, and more species in South Africa, California, and New Guinea.
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Botanical Terms -Acanthaceae (order Lamiales)
a family that is primarily composed of shrubs and has simple, opposite, and decussate leaves. The flowers are zygomorphic and bisexual, with frequently ostentatious bracts. There are two to four epipetalous stamens, four fused petals and sepals, a superior, bilobar ovary, and many, axile (see PLACENTATION) ovules. A *capsule is the fruit. Many ornamentals are present, such as Thunbergia, Aphelandra, and Acanthus. There are roughly 4000 species in 200 genera, the most of which are tropical with a few exceptions that are temperate.
a family that is primarily composed of shrubs and has simple, opposite, and decussate leaves. The flowers are zygomorphic and bisexual, with frequently ostentatious bracts. There are two to four epipetalous stamens, four fused petals and sepals, a superior, bilobar ovary, and many, axile (see PLACENTATION) ovules. A *capsule is the fruit. Many ornamentals are present, such as Thunbergia, Aphelandra, and Acanthus. There are roughly 4000 species in 200 genera, the most of which are tropical with a few exceptions that are temperate.
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Botanical Terms - Acanthus (*Acanthaceae family)
a genus of shrubs and perennial herbs, the majority of which have spiky leaves and are *xeromorphic. Certain species are grown for their aesthetic value. The *corolla's upper lip is absent. It is said that the ornamentation on Corinthian column capitals is patterned after A. spinosus leaves. There are 30 species recognized, distributed throughout Africa, Asia, and southern Europe (A. mollis grows in bear breech), as well as mangrove swamps in Asia (A. illicifolius).
a genus of shrubs and perennial herbs, the majority of which have spiky leaves and are *xeromorphic. Certain species are grown for their aesthetic value. The *corolla's upper lip is absent. It is said that the ornamentation on Corinthian column capitals is patterned after A. spinosus leaves. There are 30 species recognized, distributed throughout Africa, Asia, and southern Europe (A. mollis grows in bear breech), as well as mangrove swamps in Asia (A. illicifolius).
