Pollenkitt and viscin
threads: their role in cementing pollen grains.
Orbicules have not been observed in taxa with viscin
threads, elastoviscin, massulae or compact pollinia (Pacini, 1997).
Of these viable fruits, 7 had normal cotyledons, which were placed to germinate without the seed coat, i.e., exocarp = peel and viscin
, and one with the seed coat.
The main components of bitter melon, Charantia, viscin
and polypeptide B are thought to be responsible for its hypoglycaemic and insulin-like effects.
Apoptosis inducing activity of viscin
, a lipophilic extract from Viscum album L.
A mixed-pollen treatment was not performed because Euphorbia pollen, which contains viscin
threads, formed aggregations and it was not feasible to mix pollen evenly.
Hermaphroditic flowers develop from leaf axils and have eight stamens (with pollen connected by viscin
threads), and a cross-shaped stigma (Eisendrath 1978).
Ontogeny of Calliandra--massulae (Mimosaceae: Ingeae), and the associated viscin
This method assumes that there is no loss of pollen during the sequence, which is reasonable, as the individual pollen massulae are bound together tightly by elastic viscin
threads (Darwin 1877).
Nonapertural exine sculpturing (Walker & Walker, 1984): (0) reticulate, beaded, spinulose, or verrucate; (1) reticulate, smooth, without tectal spinules; (2) tectum with insular protrusions; (3) rugulate, imperforate, with viscin
threads; (4) psilate; (5) clavate.
in their fruits can influence quality of dispersal by causing birds to wipe defecated seeds on branches of a diameter appropriate for germination and establishment (Reid 1989, 1991, Sargent 1995).