Datta P C, Dasgupta A
Acta Biol Acad Sci Hung. 1977;28(1):81-96.
Medullary bundles of Piperaceae resemble those of Ranunculaceae. The nature of tracheary elements of primary xylem suggests that Houttuynia cordata (Saururaceae), Piper cubeba (Piperaceae) and Chloranthus officinalis (Chloranthaceae) are of lower evolutionary status than others. Among these three, P. cubeba shows stratification of secondary xylem, a specialized character. Lateral wall of metaxylem tracheary elements and distribution of bundles of Peperomia, suggest their primitive status and distinctness, supporting separation of "Peperomiacea:" (of NOVAK). Piper cubeba, Houttuynia and Chloranthus bear one important Ranunculaceous character: scalariform perforation in primary vessels. Primitive species of Peperomia carry probably another Ranunculaceous character, i.e., many circles of medullary bundles. Shape and pattern of vascular bundles of Piper cubeba, Houttuynia and Chloranthus are similar. Other species of Piper show modifications. Peperomia represents another distinct pattern.
胡椒科的髓束与毛茛科的相似。初生木质部管状分子的性质表明，蕺菜（三白草科）、荜澄茄（胡椒科）和金粟兰（金粟兰科）的进化地位低于其他植物。在这三种植物中，荜澄茄具有次生木质部分层这一特殊特征。后生木质部管状分子的侧壁以及豆瓣绿属的束状分布表明它们的原始状态和独特性，支持“豆瓣绿科”（诺瓦克提出）的划分。荜澄茄、蕺菜和金粟兰具有一个重要的毛茛科特征：初生导管中的梯状穿孔。豆瓣绿属的原始物种可能还具有另一个毛茛科特征，即多圈髓束。荜澄茄、蕺菜和金粟兰的维管束形状和模式相似。胡椒属的其他物种则表现出变异。豆瓣绿属呈现出另一种独特模式。
