A pollinium (pl.: pollinia) is a coherent mass of pollen grains in a plant that are the product of only one anther, but are transferred, during pollination, as a single unit.[1][2] This is regularly seen in plants such as orchids and many species of milkweeds (Asclepiadoideae). 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.[1]
Most orchids have waxy pollinia. These are connected to one or two elongate stipes,[clarification needed][3] which in turn are attached to a sticky viscidium, a disc-shaped structure that sticks to a visiting insect.[2]
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.
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.[1]
Milkweed pollinia are housed within a stigma chamber at the bottom of anther slits of its flower. A pollinating insect often stumbles in such a way that its legs fall down the slits, then pull up the pollinia as it tries to free its legs; the pollinia can be carried to another flower and dropped down the latter's slits to achieve pollination. However, the insect sometimes fails to retract its legs from the slits and is trapped there until it dies. [4][5]
The waxy pollinia of a Phalaenopsis
Pollinia of a Phalaenopsis orchid
Pollinium of Ophrys apifera
Pollinia of Asclepias syriaca
Male bee (Eucera cinnamomea) with pollinium attached to its head
Honeybee on antelope horn (Asclepias asperula) with pollinia attached to legs
Pollinia of milkweed (Asclepias) on the legs of carpenteer bee (Xylocopa virginica)
Pollinia of milkweed (Asclepias) on the legs of bald-faced hornet (Dolichovespula maculata)
Honeybee with a leg trapped in common milkweed pollinia slits
^ abcBeentje, H.; Williamson, J. (2010). The Kew Plant Glossary: an Illustrated Dictionary of Plant Terms. Royal Botanic Gardens, Kew: Kew Publishing.
^ abHickey, M.; King, C. (2001). The Cambridge Illustrated Glossary of Botanical Terms. Cambridge University Press.
^Kull, T.; Arditti, J. (2002). Orchid Biology VIII: Reviews and Perspectives. 8. Kluwer Academic Publishers. p. 127. ISBN 9781402005800.
A pollinium (pl.: pollinia) is a coherent mass of pollen grains in a plant that are the product of only one anther, but are transferred, during pollination...
there is a chance a pollinium would slip into an empty stigmatic slit, dislodge, and remain there. If the orientation of the pollinium is correct and the...
pulls the pollinium out of the anther, as it is connected to the viscidium by the caudicle or stipe. The caudicle then bends and the pollinium is moved...
such a bee visits another flower, this flower might be pollinated by the pollinium.[citation needed] Stem : Erect, branched, cylindrical, solid, contains...
this releases the bent pedicel which springs straight and fires the pollinium, sticky disc first, at the insect. Charles Darwin described in Fertilisation...
pollinium is detached from the flower when the bee flies away. When the bee visits another flower, the flower is pollinated by the adhering pollinium...
present. The apical part of the middle stigma lobe forms a stipe ( = pollinium stalk). The ovary is unilocular. The leaves are distichous or spiraling...
gave us the special description terminology for the orchids, such as pollinium and gynostemium. The genus Richardia Kunth, (Araceae) was named in his...
pollen of orchids is grouped in compact masses called pollinia (singular: "pollinium"), so that by itself or by wind action the pollen cannot disperse from...
pollen-grains cohering by a waxy texture or fine threads into a single body; pollinium, e.g. in orchids. pollen transmitting tissue the tissue in the style of...
one places in contact with the stigma a complete mass of pollen [i.e., pollinium], or just a part of that mass, for just one of these, cut into eight or...
indistinguishable from the insect's natural pheromones. The pollinator then has a pollinium attached to its body, which it transfers to the stigma of another flower...
one places in contact with the stigma a complete mass of pollen [i.e., pollinium], or just a part of that mass, for just one of these, cut into eight or...
orchid attracts a male orchid bee in search of a mate and attaches its pollinium onto the bee's back, providing the bee with fragrances to attract a mate...
flowers but are not adapted to their pollination mechanisms. The milkweed pollinium is collected when the tarsus (foot) of an insect falls into one of the...
cardamom, or cinnamon. The pollinia are superposed on a stipe (a cellular pollinium stalk), which is held by a viscid disc. The genus is closely related to...
time of origin of the Orchidaceae to the Mesozoic. Morphology of the pollinium suggests that M. caribea is closely related to the modern genus Ligeophila...
that either glues a "pollinium" (a pollen sack) on their body (if the flower has not yet been visited) or removes any pollinium that is there (if the...
pollinations. Depending on the morphology of the flower, a pollen sac called a pollinium is attached to the head or abdomen of the male. This is then transferred...
attempt to mate with the flower and are held in place by hooks while the pollinium is transferred between insect and flower. Orchids in the genus Arthrochilus...
epidendroids. The striking characteristics of the vandoids are a cellular pollinium stalk (= stipe), superposed pollinia and the unique development of the...
insect's head and back on the column thereby picking up pollinium load, or placing the pollinium on the stigma if the insect already carries a load on its...
throughout June and July. The diploid chromosome count is 2n = 38. Each pollinium is completely divided into two unequal halves. The seeds are 238.7 μm...
Darwin had shown its "truly marvellous" mechanism, by which it shot out a pollinium at any insect touching a part of the flower "with sticky gland always...
There is a fleshy green callus near the base of the labellum and the pollinium is burgundy-coloured. The species was first described in 1891 by Frederick...
column by a short neck at base; pollinarium with 2 obovoid pollinia, each pollinium 1.2 x 1.5 mm, cleft, attached by a thin transparent and elastic caudicle...
the purpose. In more primitive species in the genus Eulaema, the orchid pollinium, a packet of pollen, adheres to the male bee as it reverses out of the...
Global Information
The waxy pollinia of a Phalaenopsis
Pollinia of a Phalaenopsis orchid
Pollinium of Ophrys apifera
Pollinia of Asclepias syriaca
Male bee (Eucera cinnamomea) with pollinium attached to its head
Honeybee on antelope horn (Asclepias asperula) with pollinia attached to legs
Pollinia of milkweed (Asclepias) on the legs of carpenteer bee (Xylocopa virginica)
Pollinia of milkweed (Asclepias) on the legs of bald-faced hornet (Dolichovespula maculata)
