A pollinium (plural pollinia) is a coherent mass of
pollen
Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametop ...
grains in a plant that are the product of only one
anther
The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10
Morphology and terminology
A stamen typically consists of a stalk called the filam ...
, but are transferred, during pollination, as a single unit.
This is regularly seen in plants such as
orchid
Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant.
Along with the Asteraceae, they are one of the two largest families of floweri ...
s and many species of milkweeds (
Asclepiadoideae
The Asclepiadoideae are a subfamily of plants in the family Apocynaceae. Formerly, they were treated as a separate family under the name Asclepiadaceae, e.g. by APG II, and known as the milkweed family.
They form a group of perennial herbs, twi ...
). Usage of the term differs: in some orchids two masses of pollen are well attached to one another, but in other orchids there are two halves (with two separate viscidia) each of which is sometimes referred to as a pollinium.
[
Most orchids have waxy pollinia. These are connected to one or two elongate stipes,][
Some orchid genera have mealy pollinia. These are tapering into a caudicle (stalk), attached to the viscidium. They extend into the middle section of the ]column
A column or pillar in architecture and structural engineering is a structural element that transmits, through compression (physical), compression, the weight of the structure above to other structural elements below. In other words, a column i ...
.
The pollinarium is a collective term that means either (1) the complete set of pollinia from all the anthers of a flower, as in Asclepiadoideae, (2) in Asclepiadoideae, a pair of pollinia and the parts that connect them (corpusculum and translator arms), or (3) in orchids, a pair of pollinia with two viscidia and the other connecting parts.[
Image:Pollinia Phalaenopsis (1).jpg, The waxy pollinia of a ''Phalaenopsis''
Image:Phaleanopsis pollinia.jpg, Pollinia of a '']Phalaenopsis
''Phalaenopsis'' (), also known as moth orchids, is a genus of about seventy species of plants in the family Orchidaceae. Orchids in this genus are monopodial epiphytes or lithophytes with long, coarse roots, short, leafy stems and long-lasti ...
'' orchid
Image:Ophrys apifera flower2-der.jpg, Pollinium of ''Ophrys apifera
''Ophrys apifera'', known in Europe as the bee orchid, is a perennial herbaceous plant of the family Orchidaceae. It serves as an example of sexually deceptive pollination and floral mimicry, as well as of a highly selective and highly evolved ...
''
File:Eucera cinnamomea with pollinium 1.jpg, Male bee (''Eucera cinnamomea'') with pollinium attached to its head
File:Bee on Antelope Horn-April 2015.JPG, Honeybee on antelope horn (''Asclepias asperula
''Asclepias asperula'', commonly called antelope horns milkweed or spider milkweed, is a species of milkweed native to the Southwestern United States and northern Mexico.
Description
It is a perennial plant growing to 0.3–0.9 m (1–3 ft) tal ...
'') with pollinia attached to legs
File:Xylocopa virginica pollinia closeup.jpg, Pollinia of milkweed (''Asclepias'') on the legs of carpenteer bee (''Xylocopa virginica
''Xylocopa virginica'', sometimes referred to as the eastern carpenter bee, extends through the eastern United States and into Canada. They are Sympatry, sympatric with ''Xylocopa micans'' in much of southeastern United States. They nest in variou ...
'')
References
{{Commons, Pollinium (Orchidaceae)
Pollination
Plant anatomy
Orchid morphology