In Botany, What Does Actinomorphic Mean?

Actinomorphic flowers are characterized by their radial symmetry, which allows them to be divided into two equal vertical halves by any vertical plane. This type of flower is found in the petunia, buttercup, and wild rose, where the different members of each whorl are alike. On the other hand, Zygomorphic flowers are bilaterally symmetrical, which includes flowers with multiple lines of symmetry.

An actinomorphic flower can be divided into three or more identical parts, each identical to each other based on the rotating point of the center of the flower. This type of flower is found in the rose and tulip, and is a type of floral symmetry. Actinomorphic flowers are also known as star-shaped and radial, and can be divided into two equal vertical halves by any vertical plane.

In terms of floral symmetry, actinomorphic flowers are characterized by their ability to be divided into equal halves along any diameter. This type of flower is also found in the botany of flowers, such as buttercups.

In summary, actinomorphic and Zygomorphic flowers are distinct types of flowers that possess radial symmetry and can be divided into two equal vertical halves by any vertical plane.

What is difference between Actinomorphic and Zygomorphic?

Flowers have radially symmetrical (actinomorphic) lines of symmetry, while those with only a single line are bilaterally symmetrical (zygomorphic). Most flowers consist of four whorls, and if all are present, the flower is complete and perfect. If any whorl is missing, the flower is incomplete. If one of the missing whorls is either the androecium (pollen-producing) or gynoecium (seed-producing), the flower is also imperfect.

The ovary position can also distinguish between flowers. If the other whorls meet below the ovary, the flower is superior (on top of the rest), while the rest of the flower parts are below the gynoecium, making the flower hypogynous (below the gynoecium).

What is zygomorphic in botany?

Zygomorphic flowers are bilaterally symmetrical, divided into two equal halves along a single vertical plane. They are found in Jasmine and Orchids. However, an aberration produces actinomorphic flowers, which are controlled by the cycloidea gene. Knocking out this gene can produce peloric flowers, like Peloric Antirrhinum. Conversely, zygomorphic flowers do not show symmetry along any plane, like Canna indica and Valerian herb.

Is tulip actinomorphic?

Tulips are large, actinomorphic, and hermaphrodite flowers with erect or pendulous structures. They are usually arranged as single terminal flowers or two to three on the end of a floriferous stem. The perianth is undifferentiated and biseriate, formed from six free caducous tepals arranged into two separate whorls of three parts each. The tepals are petaloid and brightly colored, but each whorl may be different or have different colored blotches at their bases. The inner petals have a small cleft at the top, while the sturdier outer ones form uninterrupted ovals.

The flowers have six distinct, basifixed introrse stamens arranged in two whorls of three, which vary in length and may be glabrous or hairy. The filaments are shorter than the tepals and dilated towards their base. The style is short or absent, and each stigma has three distinct lobes. The ovaries are superior, with three chambers.

During the 17th-century tulip mania, the “Semper Augustus” was the most expensive tulip, with a white color, Carmine on a blue base, and an unbroken flame right to the top. Dr Adriaen Pauw, a director of the new East India Company, owned the tulip, and his refusal to sell any flowers despite escalating offers is believed to have sparked the mania.

Are orchids Zygomorphic?

Actinomorphic flowers are found in many plant species, while zygomorphic flowers, or bilaterally symmetric, can only result in identical halves when cut in one specific plane. Orchids, for example, have zygomorphic flowers. Despite the diversity in shape, color, and structure, all flowers can be described as either actinomorphic or zygomorphic. To observe different symmetries in flowers, observe the different symmetries in plants like small purple fringed orchids.

Is chrysanthemum Actinomorphic?

The capitulum of the chrysanthemum is composed of zygomorphous female ray florets and actinomorphic bisexual disc florets, which are typical characteristics of plants in the Asteraceae family. Morphological analysis was conducted using paraffin sections and scanning electron microscopy to study the differences between ray and disc florets in early development stages.

After transitioning to flowering, the shoot apex shifted from a shoot apical meristem (SAM) to an inflorescence shoot apical meristem (IM). Involucre primordia were produced on the side of the hemispherical IM, and dome-shaped flower primordia were initiated from the axil of involucre primordia. The disc floret primordia appeared in the center part of the inflorescence, with no difference in morphology compared to the ray flower primordia at stage Ⅰ.

Petal primordia development continued at stage Ⅲ, with stamen primordia starting to form in both ray florets and disc florets. At stage Ⅲ, the ray petal became distinct from the disc petal, with the ventral domain of the petal primordia elongating at a higher rate than the dorsal domain. This resulted in longer petal primordia in the ventral domain and covering half of the flower bud in the ray floret at stage Ⅳ.

In the disc florets, the dorsal and ventral domains of the petal primordia developed synchronously and grew to completely cover the floral bud. The carpel primordia arose at this stage. Flower organs continued to grow at stages Ⅴ and Ⅵ, except for the stamen primordia in the ray florets.

The study aimed to examine the morphological differences among different inflorescence and petal forms of the Chrysanthemum. Twelve cultivars were observed at the full-bloom stage, with the classification of petal types often based on the CTMD. The flat-petal type had the lowest fusion degree in the corolla tube, with the merged portion accounting for less than one-fifth of the total petal length. The morphology of the petals was also different among the flat petal varieties.

Group II was the spoon type, where the base of the petals merges into a tube, and the upper part unfolds into a spoon shape. Group III was the highly fused group, forming a tubular petal, and more than three-fifths of the portion is merged. Slender tubular petals and thick, straight tubular petals appeared in ‘Jinsongyue’ and ‘Guohuahuabaihe’. Some tubular ones formed hook-like structures on the tips of ray florets.

Group IV was the one with irregular petals, which had multiple degrees of fusion but the distal corolla splits into various shapes. The irregular petals are divided into three types: the unguiculate type, chenille-like shape, and aristate ones.

Group Ⅴ was classified based on the morphology of the disc florets, also called the anemone type. In contrast to the non-anemone types, the petals of the disc florets in the anemone group are elongated, forming a polygonal corolla. The petal length exceeds or is slightly shorter than the pistil length in anemone types, so when in full bloom, the pistils and stamens are hidden within the petals.

To further determine the critical stages and parts of different capitulum types, the morphologies of four groups of flower heads with different petal types were observed during the early developmental stage using SEM and light microscopy. The results showed that the ring-shaped petal primordia initiated in all inflorescence types at stage Ⅱ. At stage Ⅳ, the dorsal domain of the petal primordia lagged behind the ventral domain to varying degrees in the flat type, the spoon type, and the hooked petal tubular type. The growth of the dorsal domain of the petal determined the flower type, and the morphology of the distal region of the ray petal was also determined at the early stage of flower development.

What does Actinomorphic mean in biology?

The term “actinomorphic” is used to describe a radially symmetrical, essentially symmetrical flower, such as a tulip. The term is derived from the Greek word morphos, meaning “form,” and the German actino-actino-, meaning “pertaining to actinomorphic.”

Are sunflowers Actinomorphic?

Sunflowers (Helianthus annuus) exhibit two distinct flower structures: outer (ray) flowers with a well-developed zygomorphic corolla and inner (disk) flowers with a small actinomorphic corolla. Inner disk flowers are complete, while ray flowers are sterile.

Is Orchid Actinomorphic?

Orchids are a type of flower with radial symmetry, while most flowers are actinomorphic. They have three sepals and three petals, with one of the petals being modified into a labellum or lip. The size, shape, and color of these elements are determined by the specific pollinator the orchid is trying to attract. Orchids can be propagated asexually or sexually, using methods such as vegetative propagation, backbulb cultivation, or dividing a large sympodial orchid.

For sexual propagation, orchids have a column structure with a fused stigma and anther, with a cap covering the pollina to prevent self-pollination. Orchid pollen is contained in tiny sacs on sticks, resembling tiny “Tootsie Pops”. Once pollinated, an orchid produces a seed capsule containing up to tens of thousands of “naked” seeds, which must germinate in the correct environment and fungus to produce nutrients for burgeoning embryos.

Are orchids actinomorphic?

Orchids are a type of flower with radial symmetry, while most flowers are actinomorphic. They have three sepals and three petals, with one of the petals being modified into a labellum or lip. The size, shape, and color of these elements are determined by the specific pollinator the orchid is trying to attract. Orchids can be propagated asexually or sexually, using methods such as vegetative propagation, backbulb cultivation, or dividing a large sympodial orchid.

For sexual propagation, orchids have a column structure with a fused stigma and anther, with a cap covering the pollina to prevent self-pollination. Orchid pollen is contained in tiny sacs on sticks, resembling tiny “Tootsie Pops”. Once pollinated, an orchid produces a seed capsule containing up to tens of thousands of “naked” seeds, which must germinate in the correct environment and fungus to produce nutrients for burgeoning embryos.

What is the definition of Actinomorphic in botany?

An actinomorphic flower is a type of flower that exhibits radial symmetry, which allows it to be divided into three or more identical parts based on the rotational point of the center.

What is a regular or Actinomorphic flower?

The flower is considered regular when the members of each whorl are alike, a condition known as actinomorphic or radially symmetrical. This is exemplified by the petunia, buttercup, and wild rose. Conversely, the flower is considered irregular when differences in size or shape occur. This is exemplified by the canna and Asiatic dayflower.