J Syst Evol ›› 1988, Vol. 26 ›› Issue (5): 343-352.

• Research Articles • Previous Articles     Next Articles

Pollen Morphology of Caprifoliaceae from China and Its Taxonomic Signi-ficance

Hu Chia-Chi, He Chao-Xing   

  1.  (Department of Biology, Fudan University, Shanghai)
  • Published:1988-10-18

Abstract: The pollen morphology of 54 samples representing 12 genera and 31 species was investigated with the aid of scanning electron microscope. Observed were pollen grains of Sambucus, Viburnum, Lonicera, Leycesteria, Heptacodium, Linnaea, Abelia, Dipelta, Kolkwitzia, Symphoricarpos, Triosteum, Weigela. Based on the shape, size, position and number of aperture, exine sculpture, three types are recognized: 1. Pollen grains subprolate, less frequently prolate, rather small, 3-colporate, exine reticulate, as in Sambucus, Viburnum. 2. Mostly spheroidal, subolate, bigger than the former, also 3-colporate, exine spinulose as in Lonicera, Leycesteria, Heptacodium, Triosteum, Linnaea, Abelia, Dipelta, Kolkwitzia, Symphoriocarpos, Weigela. 3. Spheriodal, more or less flattend, exine scabrous as in Abelia section Zabelia and Lonicera section Isoxylosteum. 1. The systematic position of Caprifoliaceae: It has been generally treated as a member of the order Rubiales together with Rubiaceae, Valeriaceae and Dipsacaceae on floral characters. In respect to serological character, it has a close relationship with Cornaceae, and was placed in Araliales. The above stated 2nd and 3rd types of pollen grains are similar to those of Patrinia (Valerianaceae), Scabiosa (Adoxaceae), Cornus (Cornaceae), and the pollen grains of the 1st type are similar to those of Styraceae, Genetianaceae and Araliaceae. Taking the information so far available into consideration, the authors agree to the Cronquists treatment retaining Caprifoliaceae in the order Dipsacales together with Adoxaceae, Valerianaceae and Dipsacaceae. 2. The division of tribes: Formerly Sambuceae included the genera Sambucus and Viburnum. Fritsch (1891) segregated Viburnum from Sambuceae and suggested a new tribe Viburneae including Triosteum. There is distinct difference in palynological features between these two genera. The exine sculpture of Viburnum is reticulate, but that of Triosteum is spinulose. It is reasonable to separate another new tribe, Triosteae, from Viburneae. 3. The pollen morphorlogy of several Chinese endemic genera, such as Heptacodium, Dipelta, Kolkwitzia resembles that of Lonicera, Leycesteria, Linnaea, Symphoricarpos, Abelia, Triosteum. This evidence supports the foregoing treatment including them in Caprifoliaceae. 4. Two different exine sculptures are shown in sections of the genera Abelia and Lonicera. In Abelia the exine of the section Euabelia is spinulose, but that of the section Zabelia is scabrous. Likewise, in Lonicera, the exine of the section Isoxylosteum is scabrous, while that of other sections such as Nintooa, Isika, Lonicera, subgenus Caprifolium, is spinulose. It shows that pollen morphology is one of diagnostic characters for section division.

Key words: Pollen Morphology, Caprifoliaceae