A pseudanthium , also called flower head or composite interest , is a special kind of inflorescence, wherever from small groups to hundreds or sometimes thousands of flowers are grouped together to form a single flower-like structure. Pseudanthians take various forms. The individual flowers of the pseudanthium are commonly called florets. The actual flowers (flower buds) are generally small and often greatly reduced, but the pseudanthium itself can sometimes be very large (as in the heads of several varieties of sunflower).
Pseudanthians are characteristic of the daisy family and the sunflower (Asteraceae), whose flowers are distinguished into flower rays and disk flowers, unique to this family. Flower disks in the center of the pseudanthium are actinomorphic and the corola fused into a tube. Flowers on the periphery are zygomorphic and corolla has one large lobe (the so-called "petals" daisy are individual flower rays, for example). Either light or disc may not exist in some plants: Senecio vulgaris has no flower of light and Taraxacum officinale has no disk interest. The pseudanthium has whorl of bracts under the flower, forming an involucre.
In all cases, pseudanthium (inflorescence) is indistinguishable from the flower, but a closer examination of the anatomy will reveal that it is composed of many flowers. Thus, the pseudanthium represents the convergence of the inflection of the inflorescence to a diminished reproductive unit which can function in pollination like a single flower, at least in an animal pollinated plant.
Video Pseudanthium
Related terms
Head
This is an equivalent term for flower and pseudanthium heads when used in a botanical sense.
Capitulum (capitula plural)
Capitulum can be used as an appropriate synonym for pseudanthium and flower head; But its use is generally but not always limited to the Asteraceae family. At least one source defines it as a small flower head. In addition to the use of botany as a term that means the flower head is also used to mean the top of the sphagnum plant.
Calathid (calathids plural or calathidia)
This is a very rarely used term. It was defined in the 1966 book, The Flowering Plant Genera (Angiospermae), as a special term for flower heads of plants in the Asteraceae family. However, the on-line botanical glossary does not define it and Google Scholar does not link to the significant use of the term in a botanical sense.
Maps Pseudanthium
Plant family
Pseudanthia terjadi pada famili tumbuhan berikut:
- Apiaceae - pseudanthia disebut umbels
- Araceae - pseudanthia disebut spadices
- Asteraceae
- Campanulaceae
- Centrolepidaceae
- Cornaceae
- Cyperaceae
- Dipsacaceae
- Euphorbiaceae - pseudanthia disebut cyathia
- Eriocaulaceae
- Hamamelidaceae
- Moraceae
- Poaceae
- Pontederiaceae - by Hydrothrix
- Proteaceae
- Rubiaceae
- Saururaceae - says Anemopsis
In some families it is unclear whether the 'flower' represents pseudanthium, because anatomical work has not been done (or is still ambiguous because of the considerable evolutionary reduction). Possible pseudanthas of this type can occur in the following families:
- Hydatellaceae
- Lemnaceae
- Pandanaceae
- Triuridaceae
- Phyllanthaceae
Gallery
References
Source of the article : Wikipedia
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