Intrusive cavities in Euphorbiaceae fibre walls

Abstract

Fibres with intrusive cavities were present in Alchornea sidifolia, Alchornea triplinervia, Croton floribundus, Sapium glandulatum, and Sebastiania serrata (Euphorbiaceae). These cavities are the result of an intrusive growth of fibres which detour when they encounter a cellular obstacle, form either a fork or a concavity around the obstacle, and subsequently unite. The term 'intrusive cavity' is proposed for this structure.