J Syst Evol ›› 1998, Vol. 36 ›› Issue (2): 106-110.

• Research Articles • Previous Articles     Next Articles

The Restoration of the Genus Cyclocodon ( Campanulaceae) and Its Evidence from Pollen and Seed-coat

HONG De-Yuan, PAN Kai-Yu   

  • Published:1998-03-10

Abstract: The genus Cyclocodon Griff. was reduced by C. B. Clarke in 1881 into a section of the genus Campanumoea. Our LM and SEM observations on pollen morphology show that the pollen of all the three species in the former is 3-colporate with the exine sparsely high-spinulose, whereas that of the two species in the latter is 5~8-colpate with the exine relatively densely short-spinulose. SEM observations on seed-coat indicate that the primary ornamentation of the seed-coat of the two species in Campanumoea (s. str. ) is characterized by regular and polygonal areoles which are much larger than the radial walls in diameter and by the bead-like secondary ornamentation on the radial walls, while that of the three species in Cyclocodon is characterized by irregular-shaped areoles which are nearly equal to the radial walls in diameter and by the rope-like secondary ornamentation on the radial walls. Thus, the pollen morphology is closely correlated with the seed-coat morphology. Taking the characteristics of pollen, seed-coat and gross morphology into consideration, the genus Cyclocodon is restored, separate from Campanumoea (s. str. ). One new combination, Cyclocodon celebicus (B1.)Hong, is made in the present paper. The genus Cyclocodon is con-sidered closely related to Platycodon rather than to Campanumoa.

Key words: Campanulaceae, Campanumoea, Cyclocoden, Pollen, Seed-coat, Taxonomicalrevision