Pink Evening Primrose

What’s happening: First flush of green from bases of needle grass and my neighbor’s globe willow; Russian thistles on the move; Russian olive, juniper and pyracantha berries persist.

What’s still green: Evergreen, yucca, grape hyacinth, Jupiter’s beard, gypsum phacelia, pink evening primrose, broom senecio, snakeweed, chrysanthemum leaves; some grasses; new leaves in black-eyed Susan rosettes; winecup, tansy and tumble mustard germinating.

What’s grey, blue-grey or grey-green: Piñon, four-winged salt bush, yellow alyssum and winterfat leaves; stickleaf germinating.

What’s red/turning red: Cholla, Madonna lily, golden spur columbine, small-leaved soapwort, beardstongue, yellow evening primrose, creeping mahonia leaves; rose and young tamarix stems.

What’s yellow/turning yellow: Globe and weeping willow branches.

What’s blooming inside: Zonal geraniums.

Animal sightings: Hornet on inside porch; small birds out early on peach.

Weather: Warm afternoons chased off by cold winds; snow lingers in Jemez and Sangre de Cristo; last snow 2/4/11; 11:18 hours of daylight today.

Weekly update: Pink evening primroses fit the expectations of Spencerian ecologists who believe species are inherently aggressive and only kept in control by equally aggressive competitors.

Oenothera speciosa is native to tall grass prairies that stretch from Kansas and Missouri down through Texas into Coahuila and Chihuahua. Its branch of the Onagrace family developed in the Madrean Floristic region of today’s intermontane southwestern deserts during the Eocene when the Rockies were first being formed and grasses were evolving some 34 to 54 million years ago. The Oenothera diversified later to the east.

The five-petaled, cup-shaped flowers are white in the northern part of their range, but rosy purple with twice the chromosomes from central Texas south. In particularly hot summers here, they stop blooming in July, but resume with the monsoons and continue even after morning temperatures fall below 32.

The red anthocyanin pigments may be part of their defensive strategy against hostile conditions. The leaves turn burgundy in autumn. This past year some turned color the end of October, just before the hard freeze. More were red after temperatures fell below 20 in mid November. The stems connecting leaves to the crowns of some plants still have a reddish tint.

Despite the frigid winter, my plants kept some green leaves all winter under the protection of dead hollyhock leaves. They contain moderate levels of crude protein which deer and cattle don’t find particularly interesting in the summer. However, come winter, when little else is available, they’re palatable.

Buffalo don’t tend to eat them in summer, but they kill so many other plants with their hooves and mouths that the plants thrive. Their rhizomatous roots spread out into the newly barren areas which they quickly stabilize against the winds. They probably are choked out when the grasses reestablish themselves.

The ability to expand vegetatively is probably another adaption to life on the prairies. Grasshoppers eat the petals, sometimes before the flowers, which only live a day, can attract bees to pollinate them. As it is, the effectiveness of the bees decreases as they move from flower to flower, and the plants must be cross-fertilized to reproduce.

Temperature and day length controls their lives. Jelitto Seeds reports they germinate rapidly at about 68 degrees, then should be moved to a cooler location to grow. Beth Fausey and Art Cameron found nursery plants that spent five weeks at 40 degrees bloomed quickly, while those that weren’t vernalized would only bloom when days were 16 hours long.

For true Spencerians, the most dangerous thing anyone can do is introduce a species into a new environment where there are no natural predators. In the middle 1980's nurserymen were looking for new perennials for the new McMansion suburbs. Wayside Gardens offered its first Mexican evening primrose, Rosea, in 1987, while the more specialist Lamb Nurseries was already selling one as Berlandieri. In the early 1990's, Weiss Brothers added Siskiyou and Woodside White.

When the pink evening primroses were planted in areas where there’s more water like California and east of the Mississippi, the plants became pests. Garden websites are filled with complaints from people who treated them like other herbaceous perennials, only to have them overrun their beds and choke out the peonies, hostas and other more expensive, more cherished plants.

Before the complaints became loud, the species had become so popular with nurserymen, they were sold in the local hardware store in the early 1990's. One person in the village was able to nurture a row on the slope between a chain link fence and a dirt drive that got more than a foot high and were covered with pink flowers from mid May through summer.

I had more problems getting them established in my harsher environment. All the plants I bought, from whatever source, died. Most of the seeds I planted either didn’t germinate or were stolen by ants or birds. The fact my flowers are light pink with deeper colored veins may come from the climate or from the selection sold by Jelitto, the likely German source for the seeds I bought in 2004 and 2005. In 2006 seeds came from Oregon, the home of the Siskiyou mountains. Other years their origin was listed as Holland or the US.

The corollary to the theory of ecological balance is that plants, no matter how successful they may be, usually are unprepared for new threats. In 2003, some kind of metallic green beetle arrived in June. Hordes appeared after I got home in the evening and covered the wood fence, where I tried spraying them. Of course they moved off as soon as I appeared. My only hope was that the residue on the fence would kill or deflect them.

The only thing they ate was the evening primroses. The native white ones never came back, while the cultivated pink ones have only begun to stick their wiry stems up through the bearded iris since 2008. The planting by the village was decimated: a few flowers appeared in 2006 and 2007, then nothing since.

The neon ladybugs were probably primrose flea beetles. Around 2000 Altica litigata began to be reported in large numbers in the southeast. They invaded Dallas in 2002, and were here a year later. Some think they always existed in the wild in weedy Oenothera species that grew around nurseries. One group found, given a choice, they preferred Siskiyou to the natives.

The more confident Spencerians who believe man is the ultimate competitor think the only way to control an invasive species is to introduce its natural predator, preferably after some tests for unintended consequences. The army has been sponsoring research into the use of flea beetles against another member of the Onagraceae, the water primrose. The Uruguayan native has naturalized in the southeast, spread to Europe, and more recently been reported clogging inland waterways in New York and Washington.

One wonders if, when they were reading Principles of Biologu, they also chanced to read Oedipus.

Notes: For complaints, see comments at Dave’s Garden and Garden Web websites, or type in the plant name with the word invasive.

Damhoureyeh, S. A. and DC Hartnett. “Effects of Bison and Cattle on Growth, Reproduction, and Abundances of Five Tallgrass Prairie Forbs,” American Journal of Botany 84: 1719:1997.

Fausey, B. A. and A. C. Cameron. “Evaluating Herbaceous Perennial Species as New Flowering Potted Crops,” Acta Horticulturae 683:207-214:2005.

Freedman, Jan E., Michael J. Grodowitz, Robin Swindle and Julie G. Nachtrieb. “Potential Use of Native and Naturalized Insect Herbivores and Fungal Pathogens of Aquatic and Wetland Plants,” U.S. Army Engineer Research and Development Center, Vicksburg, Mississippi, report ERDC/EL TR-07-11, 2007.

Jelitto Staudensamen GmbH. Onothera speciosa on company website.

Jenkins, Tracie M., S. Kris Braman, Zhenbang Chen, Tyler D. Eaton, Gretchen V. Pettis, and David W. Boyd. “Insights into Flea Beetle (Coleopetra: Chrysomelidae: Galerucinae) Host Specificity from Concordant Mitochondrial and Nuclear DNA Phylogenies,” Entomological Society of America Annals 102:386-395:2009.

Katinas, Liliana, Jorge V. Crisci, Warren L. Wagner and Peter C. Hoch. “Geographical Diversification of Tribes Epilobieae, Gongylcarpeae, and Onagreae (Onagraceae) in North America, Based on Parsimony Analysis of Endemicity and Track Compatibilty Analysis,” Missouri Botanical Gardens Annals 91:159-185:2004.

McKenney, C. B., J. A. Reinert, and R. Cabrera. “Host Resistance of Oenothera spp. (Evening Primrose) and Calylophus spp. (Sun Drops) to the Flea Beetle, Altica litigata,” Southern Nursery Association Research Conference Proceedings 48:150-153:2003.

Ortega, Isaac M. Deer and Cattle Foraging Strategies under Different Grazing Systems and Stocking Rates, 1991.

_____, Sergio Soltero-Gardea and Fred C. Bryant. “Nutrient Content of Important Deer Forage Plants in the Texas Coastal Bend,” The Texas Journal of Science 46:133-142:1994.

Schultz, P. B. D. O. Gilrein, and M. S. Dills. “Flea Beetles Damaging Perennials,” Southern Nursery Association Research Conference Proceedings 46:190-191:2001.

Wolin, Carole L. Candance Galen and Lee Watkins. The Breeding System and Aspects of Pollination Effectiveness in Oenothera speciosa (Onagraceae),” Southwestern Naturalist 29: 15-20:1984.

Photograph: Pink evening primrose leaves surviving under dead leaves, 27 February 2011.

Evening Primroses

What’s blooming in the area: Apache plume, Illinois bundle flower, lance-leaf yellow brush, datura, buffalo gourd, stickleaf, white evening primrose, velvetweed, horseweed, white sweet clover, golden hairy aster, goldenrod, bigleaf globeflower, purple mat, bindweed, rose of Sharon, purple phlox, roses, sweet pea, faded bouncing Bess, heavenly blue morning glory, cardinal climber, pink evening primrose, trumpet creeper, silverlace vine, native and farmer’s sunflowers, pumpkins and beans. Hay cut in one field near orchards.

What’s blooming in my garden, looking north: Black eyed Susan, blanket flower, golden spur columbine, lance-leaf coreopsis, chocolate flowers, perky Sue, Hartweg evening primrose, fern-leaf yarrow, Mexican hat, yellow cosmos, creeping zinnia.

Looking east: Yellow evening primrose, garlic chives, California poppy, winecup peaked, floribunda (Fashion), small and large flowered soapworts peaked, pink bachelor button, coral beardtongue, hollyhock, Shirley poppy, sweet alyssum.

Look south: Zinnia, crimson rambler morning glory, sensation cosmos, blaze, rugosa and rugosa hybrid (Elisio); red hips visible on rugosa rose.

Look west: Perennial four o’clock, purple coneflower, white phlox (David), white spurge, frikarti aster, lead plant, catmint, blue flax, sea lavender, Russian sage, purple ice plant, caryopteris.

Bedding plants: Dalhburg daisies, marigolds, sweet alyssum, snapdragons, petunias, profusion zinnia.

Animal sightings: Hummingbirds, bees, ants, worm, grasshoppers on Russian sage, small snake near eastern bed. Quail crossed road with 20 young. Gopher killed a hollyhock and tomato.

Weather: Solid rain last night and this morning; gentle rain the night before as Chris dissipated in Caribbean. Earlier, the usual hot days, cloudy afternoons, cool nights, and no useful rain.

Weekly update: Evening primroses flourish this year. The tall yellow biennials are everywhere, the white cluster by the roadside, and solitary pink cultivars unfold in village gardens. In addition, velvetweed has established large colonies, and a willow leaved gaura sprouted at the road by my drive.

I haven’t driven along the other side of the river at the right time of day to see if the Hartweg and white primroses are blooming there as well. Calylophos hartwegii usually sprawl for a short stretch along the road through Santa Clara land.

It’s easy to ascribe their triumph to cool weather, but that doesn’t explain much with biennials. They had to have had their good season several years ago; I just removed unwanted plants that started growing before this year’s plants bloomed, and so must be last year’s offspring. This year’s flowers are from plants that grew between the grasshoppers of last summer and the invasion of Japanese beetles in 2003.

Botanists would tell us survival of the genes under extraordinary circumstances is a defining characteristic of the plant family Onagraceae. In 1929 Johansen theorized from chromosome counts that the family originated when two species crossbred and produced a fertile offspring that could breed with either of its parents. This created two related, but separate strains, the one tied back to the mother, the other to the father.

This is all posited to have occurred in the area of today’s intermontane southwestern deserts during the Eocene when the Rockies were first being formed and grasses were evolving some 34 to 54 million years ago. From there, Katinas, et alia, have traced the gauras, calylophus and oenothera eastward.

The primroses (oenothera) are the fifth descendant on the dominant side. Gaura emerged three stages later. And, they’re still propagating: Gaura neomexicana coloradoensis was first reported in 1895 around Fort Collins. A hundred years later, the population is still small enough to count in Colorado, Nebraska and Wyoming.

For nearsighted people like me who only see external characteristics, yellow evening primroses (Oenothera biennis) have flowers with four large petals on tall, rangy plants that can be recognized from the road. Less obvious from a distance, the four sepals curve downward and the eight anthers protrude. The sepals of the Hartwegs merely point away from the flower, but otherwise look the same.

Velvetweeds (Gaura mollis) have smaller flowers that advertise themselves by catching morning light a foot above their leaves. It’s necessary to stop to see the tiny white petals clasped by pink sepals which survive after the petals have fallen. The anthers are as obvious.

Insects apparently don’t have the same problems recognizing them, but the sepal embracement of the petals creates a funnel that hides the nectar from all but the most specialized pollinators like moths, hummingbirds and some bees. I never see any insects or birds near my flowers; in the early morning the bees are at the catmint and caryopteris.

Velvetweed has compensated for the difficulty of attracting insects by developing rhizomatous roots. It may have been forming colonies for years underground, unnoticed until conditions favored their fluorescence this summer.

The white primroses are itinerant. When they appear, and they don’t emerge every year, they may be 50' or a 100' from their ancestors. Several years ago, they shimmered above a field near San Ildefonso for about a week. I don’t know if drought prevented them from reappearing or hungry cattle.

My natives remain short, with serrated leaves and no more than two flowers at a time that curve into shallow cups. The ones along the road grow about a foot and have a number of flowers with petals that lay flat like a cross and sepals that fuse at the tips. Mine, with their reddish stems, usually begin blooming in May and are gone by 7am. The ones by the road with their whitish stalks open this time of year and last until mid-morning.

Perennial pink primroses (Oenothera speciosa) reseed within a few feet of their parents, usually nearer the walk where there’s more water, but so far they have not naturalized. The ones that edged a drive in the village did not recover from the Japanese beetles.

The fickelness of the onagraceae clan is one feature that makes them interesting to grow, or rather watch, since they disdain domestication. Only Gaura lindheimeri is currently attracting nurserymen like Baldassare Mineo and time will tell if anything he produces survives as well as the little white primroses that migrate every year.

Notes:
Johansen, Donald A. "A Proposed Phylogeny of the Onagraceae Based Primarily on Number of Chromosomes," Proceedings, National Academy of Science 15:882-885:1929.

Katinas, Liliana, Jorge V. Crisci, Warren L. Wagner and Peter C. Hoch. "Geographical Diversification of Tribes Epilobieae, Gongylcarpeae, and Onagreae (Onagraceae) in North America, Based on Parsimony Analysis of Endemicity and Track Compatibilty Analysis," Annals, Missouri Botanical Gardens 91:159-185:2004.

United States, Department of the Interior, Fish and Wildlife Service. "Proposed Threatened Status for the Plant Gaura Neomexicana ssp Coloradoensis," Federal Register 68 (56):14060-14065:24 March 1998.