HOME

TheInfoList



OR:

In
botany Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek w ...
, a fascicle is a bundle of
leaves A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...
or flowers growing crowded together; alternatively the term might refer to the
vascular tissue Vascular tissue is a complex conducting tissue, formed of more than one cell type, found in vascular plants. The primary components of vascular tissue are the xylem and phloem. These two tissues transport fluid and nutrients internally. The ...
s that supply such an organ with nutrients.Shashtri, Varun. Dictionary of Botany. Publisher: Isha Books 2005. However, vascular tissues may occur in fascicles even when the organs they supply are not fascicled.


Etymology of fascicle and related terms

The term ''fascicle'' and its derived terms such as ''fasciculation'' are from the Latin ''fasciculus'', the diminutive of ''fascis'', a bundle. Accordingly, such words occur in many forms and contexts wherever they are convenient for descriptive purposes. A fascicle may be leaves or flowers on a short shoot where the nodes of a shoot are crowded without clear
internodes A stem is one of two main structural axes of a vascular plant, the other being the root. It supports leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and phloem, stores nutrien ...
, such as in species of ''
Pinus A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden ...
'' or '' Rhigozum''. However, bundled fibres, nerves or bristles as in tissues or the
glochid Glochids or glochidia (singular "glochidium") are hair-like spines or short prickles, generally barbed, found on the areoles of cacti in the sub-family ''Opuntioideae''. Cactus glochids easily detach from the plant and lodge in the skin, causin ...
fascicles of ''
Opuntia ''Opuntia'', commonly called prickly pear or pear cactus, is a genus of flowering plants in the cactus family Cactaceae. Prickly pears are also known as ''tuna'' (fruit), ''sabra'', '' nopal'' (paddle, plural ''nopales'') from the Nahuatl word ...
'' may have little or nothing to do with branch morphology.


In pines

Leaf fascicles are present in all
pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family (biology), family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanic ...
s, and the number of adult leaves (needles) per fascicle is an important character for identification of pine
species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...
and
genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...
. Most species have fascicles of 2 to 5 needles; only occasional species typically have as few as one or as many as six leaves to the fascicle. Variation is high between species, low within them. For example, '' Pinus flexilis'' (
limber pine ''Pinus flexilis'', the limber pine, is a species of pine tree-the family Pinaceae that occurs in the mountains of the Western United States, Mexico, and Canada. It is also called Rocky Mountain white pine. A limber pine in Eagle Cap Wildernes ...
), has fascicles of 5 needles. This pine is a member of the white pine group, ''
Pinus A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden ...
'' subgenus '' Strobus'', section '' Strobus''. In all members of the group the fascicles nearly all have five needles and the sheath at the base of the fascicle is deciduous. The fascicle sheath is another character that is important for identification. Among
North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...
n pines the sheath is persistent in all so-called
hard pine ''Pinus'', the pines, is a genus of approximately 111 extant tree and shrub species. The genus is currently split into two subgenera: subgenus ''Pinus'' (hard pines), and subgenus ''Strobus'' (soft pines). Each of the subgenera have been further ...
s and deciduous in all so-called soft pines. Thus, the fascicle sheath and number of needles can be used to identify valuable
timber Lumber is wood that has been processed into dimensional lumber, including beams and planks or boards, a stage in the process of wood production. Lumber is mainly used for construction framing, as well as finishing (floors, wall panels, w ...
pines in all seasons and many years before they are mature enough to produce cones. These two characters readily distinguish the major groups of pines (see ''Pinus'' classification). '' Pinus durangensis'' ( Durango pine) has fascicles of 6 needles, rarely 7, and is the only species in ''
Pinus A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden ...
'' with so many needles per fascicle. At the other extreme, '' Pinus monophylla'' has fascicles of one needle, rarely two. This is the only species of pine with just one needle per fascicle, and this rare and easily observed character is reflected in the
specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bo ...
''monophylla'' and in the
common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrast ...
single-leaf pinyon. Although it might strike non-botanists as illogical to apply the term "fascicle" to a stem bearing a single leaf, the justification is that the structure of the stem is consistent with other pine fascicles, which justifies generalising the term to embrace single-needle fascicles as well.


In flowering plants


Fascicles do occur in some
flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants t ...
s, though not as frequently as in many conifers. Consequently, when fascicles are present the specific epithet often refers to them. Examples include ''
Prunus fasciculata ''Prunus fasciculata'', also known as wild almond, desert almond, or desert peach is a spiny and woody shrub producing wild almonds, which is native to western deserts of North America. Description ''Prunus fasciculata'' grows up to high, exce ...
'' and '' Adenostoma fasciculatum''. Species with flowers in fascicles include ''
Aechmea biflora ''Aechmea biflora'' is a species of plant in the family Bromeliaceae. It is endemic to Ecuador. Its natural habitat is subtropical or tropical moist montane forest Montane ecosystems are found on the slopes of mountains. The alpine climate ...
'' and '' Melicytus ramiflorus'', several species of '' Malva'', and the entire genus '' Flueggea''. Some species of the family Alseuosmiaceae have flowers in fascicles. In the Bignoniaceae in the genus Rhigozum flowers are borne in fascicles from cushion-like, dwarf branchlets in the axils of leaves, and several species also bear leaves in fascicles on similar or shared branchlets.Dyer, R. Allen, “The Genera of Southern African Flowering Plants”. , 1975 Both leaf and flower fascicles occur among
Angiospermae Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...
, often as
adaptation In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the po ...
s facilitating
pollination Pollination is the transfer of pollen from an Stamen, anther of a plant to the stigma (botany), stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by Anemophily, wind. Pollinating agents can ...
, such as in many
Lamiaceae The Lamiaceae ( ) or Labiatae are a family of flowering plants commonly known as the mint, deadnettle or sage family. Many of the plants are aromatic in all parts and include widely used culinary herbs like basil, mint, rosemary, sage, savory ...
, of which some '' Lavandula'' are typical. Other plant fascicles are adaptations to achieve greater compactness for defensive reasons. For example, in ''
Opuntia ''Opuntia'', commonly called prickly pear or pear cactus, is a genus of flowering plants in the cactus family Cactaceae. Prickly pears are also known as ''tuna'' (fruit), ''sabra'', '' nopal'' (paddle, plural ''nopales'') from the Nahuatl word ...
'' cacti, spines are produced in fascicles bearing a few long
spine Spine or spinal may refer to: Science Biology * Vertebral column, also known as the backbone * Dendritic spine, a small membranous protrusion from a neuron's dendrite * Thorns, spines, and prickles, needle-like structures in plants * Spine (zoolo ...
s and many short spiny bristles (or
glochid Glochids or glochidia (singular "glochidium") are hair-like spines or short prickles, generally barbed, found on the areoles of cacti in the sub-family ''Opuntioideae''. Cactus glochids easily detach from the plant and lodge in the skin, causin ...
s).


In lower plants

''
Sphagnum ''Sphagnum'' is a genus of approximately 380 accepted species of mosses, commonly known as sphagnum moss, peat moss, also bog moss and quacker moss (although that term is also sometimes used for peat). Accumulations of ''Sphagnum'' can store wa ...
'' species bear branches in fascicles.


See also

*
Spur A spur is a metal tool designed to be worn in pairs on the heels of riding boots for the purpose of directing a horse or other animal to move forward or laterally while riding. It is usually used to refine the riding aids (commands) and to ba ...
* Fascicle (disambiguation)


References

{{reflist Plant anatomy Plant morphology