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.

中文翻译：

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果序和 samara 形态计量学和 samara 在 Allocasuarina 和 Casuarina (Casuarinaceae) 中释放的潜在机制

除了翼果空气动力学之外，翼果释放机制将有助于种子传播结果。对木麻黄科（sheoaks）澳大利亚成员的物种描述的分析表明，锥体收缩可能是一种促进翼果释放的机制。然而，对九种异罗卡苏里纳和木麻黄的锥体的测量并不支持这一假设，但在田间和烘干锥体中的翼果向外运动表明另一种机制正在发挥作用。显微镜检查显示干燥后小苞片的近端边缘是渐开线的，并且推测干燥过程中小苞片的弯曲会使翼瓣向外移动，从而抵抗重力，增强了翼瓣的释放。这项研究还揭示了现场样本（9 个物种的 1-3 个标本）与已发表的描述之间的锥体和 samara 指标不一致。这可能会导致识别的不确定性，并表明需要修改描述以更全面地涵盖自然和人为范围内的变迁。