Consequently, flowers in cymose inflorescence open in a centrifugal mode.A scorpioid cyme having all the flowers in the same plane is. The flowers are arranged in a basipetal sequence, which means that flowers start maturing from apex or the top and towards the base of its stem. It is the type of inflorescence where growth of the main stem stops after the growth of a flower.
The modifications can involve the length and the nature of the internodes and the phyllotaxis, as well as variations in the proportions, compressions, swellings, adnations, connations and reduction of main and secondary axes. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed. Uniparous cyme is of two types: (a) Scorpioid cyme: successive daughter axes develop on right and left alternately, forming a zigzag, as in Freesia.Flowers occur in inflorescences of 2-4 (Jepson 1993) scorpioid cymes and contain 5, partially-fused petals that form a star-shaped, 3-6 mm-broad white.An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. The process is repeated many times. In Anthocephalus the inflorescence.Aloe hereroensis, showing inflorescence with branched peduncleUniparous Cyme: The main axis ends in a flower below which a daughter axis is produced which again ends in a flower.
Inflorescences may be simple (single) or complex ( panicle). The fruiting stage of an inflorescence is known as an infructescence. Any flower in an inflorescence may be referred to as a floret, especially when the individual flowers are particularly small and borne in a tight cluster, such as in a pseudanthium. A flower that is not part of an inflorescence is called a solitary flower and its stalk is also referred to as a peduncle. The stalk of each flower in the inflorescence is called a pedicel. The major axis (incorrectly referred to as the main stem) above the peduncle bearing the flowers or secondary branches is called the rachis.
These structural types are largely based on natural selection. These terms are general representations as plants in nature can have a combination of types. General characteristicsInflorescences are described by many different characteristics including how the flowers are arranged on the peduncle, the blooming order of the flowers and how different clusters of flowers are grouped within it.
Leafy-bracted inflorescences: Intermediate between bracteate and leafy inflorescence.If many bracts are present and they are strictly connected to the stem, like in the family Asteraceae, the bracts might collectively be called an involucre. This use is not technically correct, as, despite their 'normal' appearance, these leaves are considered, in fact, bracts, so that 'leafy inflorescence' is preferable. Leafy inflorescences: Though often reduced in size, the bracts are unspecialised and look like the typical leaves of the plant, so that the term flowering stem is usually applied instead of inflorescence. Bracteate inflorescences: The bracts in the inflorescence are very specialised, sometimes reduced to small scales, divided or dissected.
The terminal bud keeps growing and forming lateral flowers. Indeterminate inflorescence: Monopodial (racemose) growth. In inflorescences these two different growth patterns are called indeterminate and determinate respectively, and indicate whether a terminal flower is formed and where flowering starts within the inflorescence. Terminal flowerPlant organs can grow according to two different schemes, namely monopodial or racemose and sympodial or cymose.
The indeterminate patterning of flowers is derived from determinate flowers. Other flowers then grow from lateral buds.Indeterminate and determinate inflorescences are sometimes referred to as open and closed inflorescences respectively. The terminal bud forms a terminal flower and then dies out. Determinate inflorescence: Sympodial (cymose) growth.
This pattern is called acropetal maturation. Often a vestige of the terminal bud may be noticed higher on the stem.In determinate inflorescences the terminal flower is usually the first to mature (precursive development), while the others tend to mature starting from the bottom of the stem. In many cases the last true flower formed by the terminal bud ( subterminal flower) straightens up, appearing to be a terminal flower. In an indeterminate inflorescence there is no true terminal flower and the stem usually has a rudimentary end. Based on phylogenetic analyses, this mechanism arose independently multiple times in different species.
When the bract is attached to the stem holding the flower (the pedicel or peduncle), it is said to be recaulescent sometimes these bracts or bracteoles are highly modified and appear to be appendages of the flower calyx. Other plants have the bracts subtend the pedicel or peduncle of single flowers. When the parts fused together are the same, they are connately joined.) Some plants have bracts that subtend the inflorescence, where the flowers are on branched stalks the bracts are not connected to the stalks holding the flowers, but are adnate or attached to the main stem (Adnate describes the fusing together of different unrelated parts. See ' Phyllotaxis' for in-depth descriptionsSimilarly arrangement of leaf in bud is called Ptyxis.When a single or a cluster of flower(s) is located at the axil of a bract, the location of the bract in relation to the stem holding the flower(s) is indicated by the use of different terms and may be a useful diagnostic indicator. PhyllotaxisAs with leaves, flowers can be arranged on the stem according to many different patterns.
The main groups of inflorescences are distinguished by branching. The following is based on Focko Weberling's Morphologie der Blüten und der Blütenstände (Stuttgart, 1981). When the formation of the bud is shifted up the stem distinctly above the subtending leaf, it is described as concaulescent.There is no general consensus in defining the different inflorescences.
The main kind of racemose inflorescence is the raceme ( / ˈ r æ s iː m/, from classical Latin racemus, cluster of grapes). Simple inflorescencesInflorescence of sessile disc florets forming the capitulumIndeterminate simple inflorescences are generally called racemose / ˈ r æ s ɪ m oʊ s/. Inflorescences can be simple or compound. They may contain many flowers ( pluriflor) or a few ( pauciflor).
It is characteristic of Umbelliferae. An umbel is a type of raceme with a short axis and multiple floral pedicels of equal length that appear to arise from a common point. A racemose corymb is an unbranched, indeterminate inflorescence that is flat-topped or convex due to their outer pedicels which are progressively longer than inner ones. A spike is a type of raceme with flowers that do not have a pedicel. A raceme is an unbranched, indeterminate inflorescence with pedicellate (having short floral stalks) flowers along the axis. Some passage forms between the obvious ones are commonly admitted.
The main kind of cymose inflorescence is the cyme (pronounced 'saim', from the Latin cyma in the sense 'cabbage sprout', from Greek kuma 'anything swollen'). Cymose or other complex inflorescences that are superficially similar are also generally called thus.Determinate simple inflorescences are generally called cymose. A catkin or ament is a scaly, generally drooping spike or raceme. It is characteristic of Dipsacaceae. A flower head or capitulum is a very contracted raceme in which the single sessile flowers share are borne on an enlarged stem. It is characteristic of the family Araceae.
Secondary axis still dichasial: dichasium (characteristic of Caryophyllaceae) The successive pedicels follow a zig-zag path on the same plane: rhipidium (many Iridaceae) The successive pedicels are arranged in a sort of spiral: cincinnus (characteristic of the Boraginaceae and Commelinaceae) Secondary buds develop alternately on the stem : scorpioid cyme The successive pedicels are aligned on the same plane: drepanium Secondary buds always develop on the same side of the stem: helicoid cyme or bostryx
Strictly speaking this kind of inflorescence could be called umbelliform cyme, although it is normally called simply 'umbel'.Another kind of definite simple inflorescence is the raceme-like cyme or botryoid that is as a raceme with a terminal flower and is usually improperly called 'raceme'. More than two secondary axes: pleiochasiumA cyme can also be so compressed that it looks like an umbel.
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