Infructescence and samara morphometrics and potential mechanism of samara release in Allocasuarina and Casuarina (Casuarinaceae)
Küçük Resim Yok
Tarih
2020
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Csiro Publishing
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In addition to samara aerodynamics, mechanisms of samara release will contribute to seed dispersal outcomes. Analysis of species descriptions of Australian members of the Casuarinaceae (sheoaks) indicated cone shrinkage to be a possible mechanism enhancing samara release. However, measurement of cones of nine species of Allocasuarina and Casuarina did not support this hypothesis, but outward movement of samaras both in the field and in oven-dried cones indicated that another mechanism was operating. Microscopic examination revealed that the proximal margins of the bracteoles are involute after drying, and it is postulated that incurving of the bracteoles during drying moves samaras outward against gravity enhancing samara release. This study also revealed inconsistencies in cone and samara metrics between field samples (1-3 specimens for 9 species) and the published descriptions. This could lead to identification uncertainties, and indicates the need to revise the descriptions to more fully encompass the variation in sheoaks across their natural and anthropogenic ranges.
Açıklama
Anahtar Kelimeler
anemochory, diaspore release, mechanism, seed dispersal, wind dispersal
Kaynak
Australian Journal of Botany
WoS Q Değeri
Q3
Scopus Q Değeri
Q2
Cilt
68
Sayı
2
