One of my goals is to concentrate on the propagation of a few N. American native plants that would be as prized in our garden as any Chinese or S. American novelties. The hype of using native plants in our gardens and landscapes it always cut short by their difficulty to propagate (and by the lack of available seeds collections, of course). Whatever doesn’t fit into the profile of mass-production has been abandoned or perhaps not even tried in cultivation.
Besides serving an ornamental function, expanding into cultivation a few of the hard to find and/or propagate N. American species, would serve also a conservation purpose by maintaining and enriching the genetic material/ biodiversity through sexual propagation.Conservation through cultivation, (aka propagation) has already proved its importance in a few unfortunate cases of species extinct in the wild but saved, at least temporarily, in gardens sanctuaries.
“No, no! The adventures first, explanations take such a dreadful time!” – Lewis Carroll: Alice’s Adventures in Wonderland
OK. Last year we were able to finally collect a few seeds of Polygala paucifolia –Gaywings or Fringed polygala This is a low growing plant found in dry to moist woods, in part shade. It flowers in May-June and the pink-purple flowers are quite unusual – they have 3 short and 2 long wing-like sepals and 3 joined petals with a frilly crest at the tip. Fruit is a capsule. The seeds present an appendage – elaiosome, which is associated with ant dispersal – now you see where I’m going? A bit too late and the seeds are gone. The appendage contains lipids, proteins and starch, which serve as a reward for the ants. They drag the seeds to their nests to feed their youngs on elaiosomes and thus provide the service of dispersal. I bet they are very yummy!
The germination ecology for species from Polygalaceae has not been investigated in detail. I found a study claiming that for P. paucifolia, 4 months of dry storage results in an increase in germination. Other Polygala species are known to require pre-treatments for germination. Anyway, I don’t have that many seeds, so for this year I’ll try two variants: dry storage and moist-cold stratification until sowing in the spring.
We shall see…the seed adventure continues!
Note: Many spring flowers from the temperate climate rely on ants to disperse their seed (myrmecochory – I wouldn’t try pronouncing this); from the very well known: Trillium, Hepatica, Corydalis, Dicentra…