Infructescence and samara morphometrics and potential mechanism of samara release in Allocasuarina and Casuarina (Casuarinaceae)

Küçük Resim Yok

Tarih

2020

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

Künye