It is hard to argue that there is any one flower designed more “perfectly than all the rest. I will say, however, that the survival mechanisms of some plant species can seem a bit more) clever and possess a bit more intrigue than others–for instance, those in the business of pollinator exploitation.
The common name dutchman’s pipe is an apt description of the flower of many Aristolochia species. The U-shaped flowers possess a wide mouth that quickly narrows and bends significantly upward, before expanding again to an inflated tube. A promise of nectar–or, in some cases, an odor replicating rotting flesh–invites scores of midges and flies inside. The flower amasses its prisoners until one arrives with pollen from another plant. Once fertilization is complete, the flower powders its temporary residents with pollen, opens its doors, and sends them on their way.
I first came to know the genus as a young gardener in north-central Michigan, where Aristolochia macrophylla (syn. A. duri-or) was the vine of choice to cover arbors and screens on the shady north sides of homes. The bold heart-shaped deciduous foliage provides a textural relief unlike any other hardy native vine; the curious brown-purple flowers are hidden beneath it.
This species is superficially very similar to one I first observed in the mountains of South Korea. Aristolochia man-shuriensis grows 50 feet or higher into the trees there, brandishing large heart-shaped foliage to eight inches across. Handsome yellow flowers are freely produced on the specimens in my garden, but it was in the wild where I first saw its fruit–huge sausage-shaped lavender pods to six inches in length. Both A. macrophylla and A. manshuriensis are hardy in USDA Zones 4-9.
Aristolochia californica, a diminutive species that grows to 12 feet, is perhaps the most charming in flower of all the hardy species. The smaller gray-green foliage appears in mid-spring, after the relatively large, translucent tawny pink flowers have appeared in abundance. Though all species will tolerate a great deal of shade, this species seems to appreciate a greater degree of direct sun.
The flowers of the Japanese species, A. kaempferi, though relatively small, pack a punch with color–shades of vivid yellow contrast with a deep burgundy throat. The felt gray-green leaves are linear and tri-lobed to four inches in length. This species tolerates a great deal of shade in our garden while still flowering freely. Its general hardiness is in doubt, though I suspect it would survive in Zones 6-10.
Perhaps best known of the tropical species is A. gigantea, successfully cultivated as a summer vine on the East Coast. Where sultry summer temperatures exist, gardeners will appreciate the enormous flared purple-spotted flowers that might be described as beautifully suggestive–if not simply beautiful. I wish that we could grow it in the Pacific Northwest, but sadly we cannot, because of the perpetual coolness.
But, fortunately, I can grow many others. And when I am ushering children through the garden, I will take a flower of any Aristolochia, open it, and watch a hundred midges fly away. Seeing the astonished look of undiluted amazement on tomorrows gardeners makes me feel good. For the children–and the midges.
TYPE OF PLANT: a genus of evergreen or deciduous climbers and shrubs FAMILY: Aristolochiaceae HEIGHT/SPREAD: the smallest species is a shrub 3 ft./2 ft.; the largest, a vine reaching 30 ft. in cultivation LEAVES: entire or lobed, and often heart shaped; dark or grayish green FLOWERS: thickly U-shaped, inspiring the common name of dutchman’s pipe; color can be white to yellow, purple to dark red or brownish; often spotted or mottled HARDINESS: USDAZones 4-9 [hardy speciesJ/12-15 (tropical species] SOIL: fertile and moist but well draine