Creeping Mahonia

What’s happening: Globe willow branches look browner while upper reaches of cottonwoods look whiter.

What’s still green: Evergreens, yuccas, Japanese honeysuckle, grape hyacinth, sea pink, Jupiter’s beard, stickseed, gypsum phacelia, golden spur columbine, pink primrose, blue flax, vinca, young snakeweed, broom senecio, strap leaf aster, chrysanthemum leaves; young chamisa stems.

What’s grey, blue-grey or grey-green: Piñon, four-winged salt bush, snow-in-summer, stickleaf, winterfat, golden hairy aster leaves.

What’s red/turning red: Cholla, beardtongue, Madonna lily, heath aster leaves; rose stems.

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

What’s blooming inside: Aptenia, Christmas cactus, zonal geranium.

Animal sightings: One radio station is advertising feed for jays and woodpeckers. Unless one has large land holdings left to nature, who ever would want those birds around the house and yard?

Weather: Morning temperatures usually in the low 20's; last snow 12/30/10; 9:27 hours of daylight today.

Weekly update: Winter’s a time of discovery. Since Adam, leaves have provided privacy. When they fall, the unexpected ‘s revealed.

Two weeks ago I noticed three burgundy-colored holly leaves growing under a ramp where they’d been hidden behind a raspberry. Those leaves had disintegrated. The nearby camouflaging vegetation was gone. Creeping mahonia stood exposed to the morning sun.

The ground hugging member of the barberry family is native to shady parts of the Rocky mountains from northern México into Canada. In New Mexico, the broadleaf evergreen grows between 8,000 and 10,000' with Douglas fir and white fir, where precipitation averages 25" a year. In areas too cold for white fir, Berberis repens grows with Douglas fir and Gambel oak, where the mean annual air temperature is 41 degrees and the soil frigid. Early in the twentieth century, it was reported in the Santa Fe, Las Vegas and Sandia mountains as well as up at Chama.

The only native peoples who used the berberine containing plant were the Navajo. However, Leonora Curtin found Spanish-speaking people boiled yerba de la sangre leaves to treat anemia and induce menstruation. No one mentioned eating the blue berries, which are bitter until chilled by frost.

I doubt the single unbranched stem was a native volunteer. While an established plant can tolerate a wide range of soils, temperatures and rain levels, it seems less tolerant of drought or sun at lower altitudes, where it tends to grow only on north facing slopes, and doesn’t like the drying winds of late winter.

I’m probably responsible for its appearance. I planted four grape holly seedlings in April of 2006 in that area. Two survived the year to emerge the following March, but disappeared in May with the spring moisture. They were sold by Hardy Boys, who provide seed-grown bedding plants to local stores. I assume this yellow-wooded shrub may have come from some dormant seed in one of the pots.

In ideal laboratory conditions on wet paper, Perry Plummer’s team found seeds required 30 days at 34 degrees, 60 days at 70, and then more time at 34. After more than six months (196 days) of added cold, 62% of the seeds germinated. When temperatures were returned to 70, another 12% sprouted.

Fire may produce similar results. Buried seeds can survive cold soils for years without losing viability. Roger Kjelgren found he could germinate pips by treating them with hot water before chilling them for 60 days.

In contrast, Ken Fern was able to sprout seeds in England within six weeks when he removed them from their waxy wrappers before they were fully ripened, that is after the embryos had developed but before the seed cases had dried. In Utah, Richard Stevens and Kent Jorgensen only had 25% of their fresh seed germinate.

Black bears, which inhabit the mixed conifer forests of the Jemez and Sangre de Cristo, gulp the fruit as soon as it’s available in summer, probably before the seed ripens. The seeds pass through unbroken, but germinate better than ones given the usual warm and cold treatments. Janene Auger’s group suspects that digestion may replace the heat phase so they can sprout the following spring after the cold of winter.

Bears are mobile creatures. Some distance may exist between where they forage for food or water and where they live under or in rocks and trees. Creeping mahonia does best in dappled shade, but is often the only plant growing under mature canopies on rocky or gravelly soil where it rarely blooms. In such cases, it can reproduce from new shoots emerging from underground rhizomes or can be renewed by bear droppings.

In early spring, six-petaled yellow flowers appear in clusters towards the ends of stems which get some sun, especially those near streams where bears drink. The leathery leaves respond to the brighter light by producing more red anthocyanin pigments in their outer cells that scavenge excess oxygen radicals.

When the leaves turn color in fall, the amount of red pigment in exposed leaves doubles while the photosynthesis rate decreases and the leaves begin retaining higher levels of certain xanthophyll pigments to block light. Leaves of plants in shade remain unchanged when temperatures drop.

I don’t know if the stoloniferous roots are established enough to survive this dry winter. So far we’ve had less than three inches of snow and the morning frost has been pulled more from plants and the ground than passing clouds. Two weeks ago, the edges of the leaves were brown. Last week, the dead band had increased. Yesterday, the black spot on one was larger.

It would have been better if the raspberry had managed to keep its parasol of dead leaves and let the mahonia hide in its shady wind shadow.

Notes:
Auger, Janene, Susan E. Meyer and Hal L. Black. "Are American Black Bears (Ursus Americanus) Legitimate Seed Dispersers for Fleshy-Fruited Shrubs?," American Midland Naturalist 147:352-367:2002; they saw one male bear pass nearly 60,000 creeping mahonia seeds in 24 hours.

Curtin, Leonora Scott Muse. Healing Herbs of the Upper Rio Grande, 1947, republished 1997, with revisions by Michael Moore.

Fern, Ken. "Mahonia repens - (Lindl.) G. Don.," Plants for a Future website.

Grace, Stephen C., Barry A. Logan, and William W. Adams III. "Seasonal Differences in Foliar Content of Chlorogenic Acid, a Phenylpropanoid Antioxidant, in Mahonia repens," Plant, Cell & Environment 21:513–521:May 1998.

_____, _____, _____ and Barbara Demmig-Adams. "Seasonal Differences in Xanthophyll Cycle Characteristics and Antioxidants in Mahonia repens Growing in Different Light Environments," Oecologia 116:9-17:1998.

Kjelgren, Roger. "Mahonia repens," 2003, discussed by John K. Francis, "Mahonia repens (Lindl.) G. Don.," available on-line.

Moir, W. H.. "Alpine Tundra and Coniferous Forest" in William A. Dick-Peddie, New Mexico Vegetation, 1993.

Plummer, A. Perry, Donald R. Christensen, and Stephen B. Monsen. Restoring Big-Game Range in Utah, 1968.

Stevens, Richard and Kent R. Jorgensen. "Rangeland Species Germination through 25 and up to 40 Years of Warehouse Storage," Ecology and Management of Annual Rangelands, Proceedings, 1992, published 1994.

Wooten, Elmer Otis and Paul Carpenter Standley. Flora of New Mexico, 1915; also mentions the Black Range, Tunitcha, Carrizo, Zuni, and Sacramento mountains, as well as Dulce, Ramah, and Luna.

Photograph: Creeping mahonia, 29 January 2011.