A Peculiar Ericalean Pollen, Grain

Abstract

IN the genus Styphelia Sm., the Epacridaceae include a pollen form previously not known in this or related families. I have examined the patterns of ektexine ornamentation in pollen from all genera of the Epacridaceae. The grains are mostly similar to those of allied families, in that they are either smooth or have an ornamentation which is inconspicuous except under oil immersion. Those of Styphelia, however, are strikingly different. Of the eleven species recognized by Bentham¹, I have been able to investigate ten, and in these the grains are always provided with warts (Fig. 1), the largest of which are usually conspicuous at quite low magnifications and may be more than 10µ in diameter. As can be seen in the photograph, the warts are rather easily detached, and at first sight they could be mistaken for oil droplets. The grains of S. tenuiflora and S. melaleucoides have smaller warts than do the other species, but even here they are easily distinguished from those of related groups. Similar forms occur in distant families (for example, Nymphaeaceae), but the pollen of Styphelia appears to be without parallel in the Ericales.