The magnoliid clade encompasses 18 extant families arranged in four orders, plus several extinct taxa, including some of the most ancient angiosperm fossils. The clade is characterized by paracytic stomata with a distinct pair of lateral subsidiary cells that flank the guard cells, though other stomatal types are also reported, including anomocytic and anisocytic. In contrast with monocots, the paracytic stomata of magnoliids develop from linear triads, and the lateral subsidiary cells are stomatal-lineage ground cells (SLGCs). Anisocytic stomata typically possess three SLGCs. Amplifying divisions are rare in magnoliids, but occur in some Piperales, in association with anisocytic stomata. Differences in mature stomatal types result from differences in cell shape and polarity at critical developmental stages. Stomatal clusters have been reported in Cinnamomum (Lauraceae) and Galbulimima (Himantandraceae), but neither are apparently formed by amplifying divisions, in contrast with eudicots. In Galbulimima, each peltate scale hair is surrounded by a ring of 3–8 non-contiguous stomata, each derived from different initial meristemoids.

木兰科分支包括 18 个现存科，分为四个目，以及几个灭绝的类群，其中包括一些最古老的被子植物化石。该进化枝的特征是平细胞气孔，具有一对独特的侧副细胞，位于保卫细胞两侧，但也报道了其他气孔类型，包括无细胞和异细胞。与单子叶植物相反，木兰科植物的平细胞气孔由线性三联体发育而来，侧向附属细胞是气孔谱系地面细胞（SLGC）。不等细胞气孔通常具有三个 SLGC。放大分裂在木兰科植物中很少见，但在某些胡椒目中会发生，与不等细胞气孔有关。成熟气孔类型的差异是由于关键发育阶段细胞形状和极性的差异造成的。据报道，肉桂科（ Cinnamomum）（樟科）和加布米玛（Galbulimima ）（Himantandraceae）有气孔簇，但与双子叶植物不同，它们显然都不是通过放大分裂形成的。在Galbulimima中，每根盾状鳞毛都被一圈 3-8 个不连续的气孔包围，每个气孔都源自不同的初始分生组织。