Lianas and vascular variants have long been correlated since it is in lianas where they are most commonly found. Structurally, these vascular variants mix soft and stiff tissues allowing lianas to twist without breaking when climbing up to the forest canopies. The study of vascular variants in Malpighiaceae lianas has a long history focusing on species-diverse taxa; however, interest in understanding them in understudied, smaller taxa has unraveled vascular variants previously unknown to the family, such as the interxylary phloem of Henleophytum, a Cuban endemic, monospecific genus. Interxylary phloem in Malpighiaceae had been previously recorded in the distantly related genera Dicella, Niedenzuella, and Tristellateia. Interxylary phloem in Henleophytum derives from a cambium that in certain periods and sites produces phloem both inward and outward, similar to the pattern described for Dicella. The phloem produced outward is not equal to that produced inward. Indeed, sieve tube elements of the inner phloem are always much wider and more abundant, something likely indicative of a division of labor between both phloem types, one specializing in conduction and the other in carbohydrate storage. This constitutes a new report of a vascular variant outside the large Tetrapteroid clade, where almost all the vascular variants have been reported for the family so far, and supports the idea of the independent, multiple origins of vascular variants in Malpighiaceae.

藤本植物和维管束变异长期以来一直相关，因为它们最常见于藤本植物。从结构上讲，这些维管束变体混合了柔软和坚硬的组织，使藤本植物在爬上森林树冠时可以扭曲而不会断裂。对金虎尾科藤本植物维管束变异的研究有着悠久的历史，重点关注物种多样化的分类群。然而，对了解未充分研究的较小类群的兴趣已经解开了该科以前未知的维管束变异，例如古巴特有的单一属的Henleophytum的木质部韧皮部。金虎尾科的腋间韧皮部先前已在远缘亲缘属Dicella、Niedenzuella和Tristellateia中记录到。Henleophytum中的腋间韧皮部源自形成层，该形成层在某些时期和地点产生向内和向外的韧皮部，类似于Dicella描述的模式。向外产生的韧皮部不等于向内产生的韧皮部。事实上，内部韧皮部的筛管元件总是更宽、更丰富，这可能表明两种韧皮部类型之间的分工，一种专门负责传导，另一种专门负责碳水化合物的储存。这是关于四翼类大分支之外的维管变异的新报告，迄今为止，该科几乎所有维管变异都已报道，并支持金虎尾科维管变异具有独立、多重起源的观点。