ANATOMY OF CORTEX AND SECONDARY PHLOEM OF ROSACEAE. 2. SP1RAEOIDEAE EXCEPT SPIRAEEAE AND LYONOTHAMNEAE

摘要

The conex is nearly uniform and quite typical of dicotyledonous cortex m all 8 species studied which represent 6 genera and 3 tribes of Takhtajan's subfamily Spiraenideae. The first periderm arises, in the inner cortex, pericycle, or even in the external phloem depending on a genus. Steles of various genera differ by the prcsenceor absence of pericycle. protophtoem fibres, hard secondary phloem, simple/compound sieve plates, and by ray or phloem dilatation, respectively. The stele designs correlate neither with taxonomic position of a plant nor with its, life form. Takhtajan's tribes Cilltnieae and, perhaps, Neillieae may be heterogeneous. Deep origin of the first periderm seems to be the only common bark feature in Spiraeoideae subfamily.