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 aper-
ture, 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 sphe-
roidal, subolate, bigger than the former, also 3-colporate, exine spinulose as in Lonicera, Ley-
cesteria, Heptacodium, Triosteum, Linnaea, Abelia, Dipelta, Kolkwitzia, Symphoriocarpos, Wei-
gela. 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 in-
formation so far available into consideration, the authors agree to the Cronquists treatment re-
taining Caprifoliaceae in the order Dipsacales together with Adoxaceae, Valerianaceae and
Dipsacaceae.
2. The division of tribes: Formerly Sambuceae included the genera Sambucus and Vi-
burnum. Fritsch (1891) segregated Viburnum from Sambuceae and suggested a new tribe Vi-
burneae 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 Loni-
cera. 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.
