gynostemium

[ jin-uh-stee-mee-uhm, gahy-nuh-, jahy- ]

noun

, Botany.

, plural gyn·o·ste·mi·a [jin-, uh, -, stee, -mee-, uh, gahy-n, uh, -, jahy-].

1. the united stamens and pistil of an orchid.

Word History and Origins

Origin of gynostemium¹

1860–65; < New Latin, equivalent to gyno- gyno- + Greek stḗm ( ōn ) warp, thread + New Latin -ium -ium

Example Sentences

This study sheds new light on the genetic mechanisms underpinning key orchid innovations, including the development of the labellum and gynostemium, pollinia, and seeds without endosperm, as well as the evolution of epiphytism; reveals relationships between the Orchidaceae subfamilies; and helps clarify the evolutionary history of orchids within the angiosperms.

From Nature

Previous studies have shown that expanded B-AP3 and E classes with members that have different expression patterns in floral organs are associated with the innovation of the unique labellum and gynostemium in orchids9, 16, 17, and that duplicated B-AP3 genes are responsible for the modularization of the perianth of orchid flowers18.

From Nature

Apostasia presents a number of characters that are plesiomorphic in orchids, such as an actinomorphic perianth with an undifferentiated labellum, a gynostemium with partially fused androecium and gynoecium, pollen that is not aggregated into pollinia, and underground roots for terrestrial growth1, 5, 6, 7.

From Nature

In conclusion, the genome sequence of A. shenzhenica, an orchid belonging to a small clade that is sister to the rest of Orchidaceae, provides a reference for studying orchid evolution, revealing clear evidence of an ancient WGD shared by all orchids, facilitating reconstruction of the ancestral orchid gene toolkit, and providing insights into many orchid-specific features such as the development of the labellum and gynostemium, pollinia, and seeds without endosperm, as well as the evolution of epiphytism.

From Nature

These similarities suggest that the lower gene numbers in MADS-box B-AP3 and E classes in Apostasia represent an ancestral state, responsible for producing the plesiomorphic flower with an undifferentiated labellum and partially fused gynostemium.

From Nature