Article: A heterophyllous cheirolepidiaceous conifer from the Cretaceous of East China
Zhou Zhiyan (Chow Tseyan)
Suturovagina intermedia Chow and Tsao (Cheirolepidiaceae) from the Cretaceous of China is redescribed and emended on the basis of abundant new material. Its leafy shoots are heterophyllous and show axillary branching. The juvenile shoots bear widely spaced scale leaves, while mature ones bear mainly broad leaves enclosing most or the whole of the stem, with either a gap or a suture between the two lateral edges. Leaves of different types of shoot are generally similar in cuticular structures. Their stomata differ from all other members of this family in the very elongated subsidiary cells which form a tube- to truncated cone-shaped projection. Some dispersed fossil secondary xylem of Protopodocarpoxylon-type proves to belong to the same plant. An associated male cone, Classostrobus cathayanus sp. nov. yielding Classopollis pollen is also referred to it. This is the largest male cone so far known from this family.