Wednesday, September 1, 2010

Wildflower Wednesday: Tickseeds & Beggarticks

'Wildflower’ is an interesting concept. One might think that it refers to a plant version of ‘wild beast’, but the connotations barely overlap. If a wildflower really did go wild, then I would soon weed it out. Thus, cultivating ‘wildflowers’ in a garden creates a certain level of cognitive dissonance. The pedant in me wonders if I should look for another name for this series of posts? But I think not, for as William Cullina states in his book Wildflowers (see sidebar) about this week’s offering: “Tickseeds are indispensible wildflowers for the sunny garden.”
Only one of the 33 species of North American tickseeds (Asteraceae: Coreopsis) is currently found growing wild in Alberta: Golden Tickseed – Coreopsis tinctoria. I don’t grow it in my garden because I’ve never come across it. I’ve tried a related native annual, Nodding Beggartick Bidens cernua, but it didn’t establish, and besides, the local wild beggarticks support large populations of the chyromelid beetle Calligrapha californica corepsivora. As pretty as the beetle is, I’d prefer that this beast stay in the wild.
The Home Bug Garden does have tickseeds, but only those that are perennial, not quite native, and dubiously wild. Given a few more millennia of postglacial thaw, several of these North American plants may have gotten to Alberta on their own, but for now they need to be transplanted or seeded. Flying Saucers - Coreopsis grandiflora ‘Walcorep’ - was my first tickseed. Although it ‘naturally’ occurs as far north as Maine and Wisconsin, my plant failed to survive its first Alberta winter. Sad, because the flowers could be envisioned as giant yellow flying saucers and made a spectacular display.
In contrast, and although only rated to Zone 4, Threadleaf Tickseed Coreopsis verticillata has done well in my Zone 3 garden. The wildflower is found in dry woods and clearings in the southeastern US (perhaps driven there by the glaciers). ‘Golden Showers’ is tallish (1 m) variety with bright golden ray flowers and has survived three years of part-sun and cold, cold winters, blooming from mid-summer to frost. ‘Moonbeam’ is a dwarfish variety (1-2 ft.) with pale lemon ray flowers. It is nearing the end of its second summer in the HBG and it is a delightful flower. The Perennial Plant Association named Moonbean 'Plant of the Year' in 1992, but I don’t think I can call this a sterile hybrid a wildflower. Treating a horticultural variety as a ‘wildflower’ stretches the concept to the breaking point, so lets not.
But all is not lost - my final tickseed should more or less count as a wildflower: Lance-leaved or Sand Tickseed - Coreopsis lanceolata. It is native to Canada, or at least Ontario and British Columbia, and my plants derive from seeds from open-pollinated plants at the nearby Devonian Botanical Garden. The seeds germinated readily last year, but all I got was a basal clump of leaves. The leaves are evergreen even in this climate and so added a little colour to the early spring. This year the flowering stalks went a metre and a half (~5 feet) and added to a nice composition of native (e.g. Helianthus maxmilliani, Rudbeckia hirta) and near native composite ‘wildflowers’ (Echinacea purpurea, Heliopsis helianthoides, Liatris spicata) in the front woodland garden.
Although bees and other pollinators come to Lance-leaved Tickseed flowers, some recent research has called attention to the plant’s usefulness in attracting insect natural enemies*. ‘Natural enemies’ in this case was rather loosely defined as any arthropod that eats or parasitizes another arthropod, so predators and parasites of pollinators counted as much as those that eat crop pests. Still, planting strips of native ‘wildflowers’ around your crops probably would contribute towards maintaining arthropod biodiversity. Companion planting of ‘wildflowers’, however, continues to erode away at the concept.
Coreopsis comes from the Greek for ‘like a bedbug’. Presumably Linnaeus thought the seeds looked like some bugs with which he was familiar, but when I was collecting tickseed seeds earlier, a Minute Pirate Bug tumbled out of the seedhead. According to Fiedler & Landis (2007) Lance-leaved Tickseed seems especially attractive to Minute Pirate Bugs (Anthocoridae: Orius) which tend to feed on small pests such as aphids, thrips, and spider mites. Anthocoridae (‘flower bugs’) also have a habit of biting people and are thought to have shared a common ancestor with bedbugs, so perhaps Linnaeus was having another of his amazing insights. Personally, I can’t see the similarity of tick-seed (both Old English words) to either bedbugs or ticks, but perhaps I’m looking at the wrong species.

*A. K. Fiedler and D. A. Landis 2007. Attractiveness of Michigan Native Plants to Arthropod Natural Enemies and Herbivores. Environ. Entomol. 36(4): 751-765.

1 comment:

  1. 'Moonbeam' has proved to be a feeble flower in our garden, although I like the pale yellow color.'Zagreb' has worked well for us, and now I see I should also try C. lanceolata. Nice pic of the spiderling tip-toeing o'er the petals!