I have frequently been asked about Lilium parryi var. kessleri, so I would like to clear up the confusion about this variety of Lemon Lily.
In 1924, Davidson defined a new taxon of Lemon Lily from the San Gabriel Mountains that he called variety kessleri based on the following characteristics:
- leaves large, ovate to lancelate, 12 to 15 cm long and 4 cm wide, sessile with a narrow base, thin in texture, semitransparent on drying and glistening on lower surface
- leaves below in whorls of 6, fewer and less definitely whorled above
- anthers brown, 5 to 7 mm long
- pistil much longer than anthers
This distinction has since fallen out of favor. Modern floras either make no mention of var. kessleri or list it as a synonym for Lilium parryi. The latest treatment from the Flora of North America states:
“Plants from the San Gabriel Mountains of California sometimes have wider leaves and have been given the status Lilium parryi var. kessleri, but this variation is due primarily to the rather shaded habitat of many of these populations. No significant vegetative discontinuity can be recognized across the range of this species, so no varieties are recognized here.”
I had noticed for some time that the leaf structure of Lemon Lilies is highly variable. Since leaf size was said to be the distinguishing factor for var. kessleri, in 2010 Tom Chester and I set about to test this claim by measuring Lemon Lily leaves wherever we found them in the San Jacintos. As expected we found plants with leaves with a wide range of sizes and shapes. Within our San Jacinto population we found some lilies that matched or even exceded the range of sizes given for var. kessleri. We also found plants with leaves that exceded the number per whorl for var. kessleri.
By reviewing his photos Tom found some flowers with yellow anthers and others that were brown. Some plants had pistils longer than the anthers, and others had pistils the same length as the anthers.
So even though some references, both old and new, still list var. kessleri we found nothing unique about it confirming what the FNA now asserts. This does not imply that all Lemon Lilies are genetically identical, but until DNA testing can prove otherwise there are no recognized varieties of Lemon Lily.
I would like to acknowledge Tom’s assistance in this analysis, and Kate Kramer for finding the complete text of Davidson’s 1924 article.