A frond is a large leaf with many divisions to it, and the term is typically used for the leaves of palms, ferns or cycads. In Botany, a leaf is an above-ground Plant organ specialized for Photosynthesis. Arecaceae or Palmae (also known by the name Palmaceae, which is taxonomically invalid or commonly palm tree) the palm family is a family of Flowering A fern is any one of a group of about 20000 Species of Plants classified in the phylum or division Pteridophyta, also known as Filicophyta Cycads are a group of Seed plants characterized by a large crown of compound leaves and a stout trunk. [1]
A frond is the leaf- like structure of a fern or alga. In Botany, a leaf is an above-ground Plant organ specialized for Photosynthesis. A fern is any one of a group of about 20000 Species of Plants classified in the phylum or division Pteridophyta, also known as Filicophyta Algae ( sing. alga are a large and diverse group of simple typically Autotrophic organisms ranging from Unicellular to Multicellular forms The term is colloquially applied to the leaves of palms, cycads, and plants with pinnately compound leaves. Arecaceae or Palmae (also known by the name Palmaceae, which is taxonomically invalid or commonly palm tree) the palm family is a family of Flowering Cycads are a group of Seed plants characterized by a large crown of compound leaves and a stout trunk. A significant difference is that, unlike the leaves of the latter, fern fronds bear the reproductive structures (spore-bearing structures) of the sporophyte plant. Because many ferns grow fronds that are held more vertical than horizontal, the "upper" and "lower" surfaces of a frond are more correctly referred to as the adaxial and abaxial surfaces, respectively.
A fern frond consists of a stipe, the stem supporting the blade, and the blade consists of both a laminar (flattened) photosynthetic tissue and a rachis—that portion of the stem to which the laminar tissue is attached. The blades of fern fronds may vary from being simple (undivided) to being highly dissected, even "lace-like". If the leaf tissue is undissected, or the dissections do not reach to the rachis, the frond may be described as lobed or pinnatifid. Otherwise, the blade is compound and each large division of the laminar tissue arising from the rachis is called a pinna (pl. , pinnae). The main vein or mid-rib of a pinna is known as a costa (pl. , costae). Pinnae may be arranged along the rachis either directly opposite one another or alternating up the stem. The arrangement may change from the base of a blade to the tip, as in the example of Blechnum shown below (from base to tip: pinnae opposite to alternate, and pinnatisect to pinnatifid).
Many ferns have pinnae that are divided two or more times, and the level of division of the fronds is termed pinnate (or 1-pinnate), or twice-pinnate (2-pinnate), or the like. Each secondary division (division of a pinna) is termed a pinnule, and its mid-vein, a costule. A few species of ferns with divided fronds are not pinnate, but are palmate or bifurcate. Pinnate is a term used to describe Feather -like or multi-divided features arising from both sides of a common axis in Plant or Animal structures and comes In Botany, the following terms are used to describe the shape of plant leaves: Acicular ( acicularis) Slender and pointed needle-like
On some or all mature blades (usually on the abaxial surface) occur sporangia, which bear the spores. A sporangium (pl sporangia) is a Plant or fungal structure producing and containing Spores Sporangia occur in angiosperms, In Biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions The sporangia are clustered in a sorus (pl. "Sori" redirects here For the commune in Italy see Sori Italy; for the villages in Azerbaijan see Soru and Sors Azerbaijan. , sori) or "fruit dot". Associated with each sporus in many species is a membranous structure called an indusium: an outgrowth of the blade surface that may partly cover the sporangial cluster. Fronds also may bear hairs or scales, glands, and, in some species, bulblets for vegetative reproduction.
Each frond arises from the stem or rhizome, which in most species is concealed in the ground or creeps along the ground (or branch or rock) surface. In Botany, a rhizome is a horizontal stem of a Plant that is usually found underground often sending out Roots and Shoots Growth of a fern frond differs from that of a leaf of a flowering plant. The flowering plants or angiosperms ( Angiospermae or Magnoliophyta) are the most widespread group The fern frond unrolls from a tightly-coiled structure called a "fiddle-head" (see circinate vernation). Vernation (from vernal, since that is when leaves "spring forth" in Temperate regions is the formation of new leaves or fronds
Some fern species feature frond dimorphism, in which fertile and sterile fronds differ in appearance and structure. Frond dimorphism refers to a difference in Ferns between the fertile and sterile Fronds Since ferns unlike Flowering plants, bear Spores
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