Other October Events
• Itinerant black bears feast on wild fruits, raid garbage cans and climb trees to nap.
• Western rattlesnakes converge on communal hibernating sites in rocky hillsides and prairie dog colonies.
• Elk bulls bugle to attract harems along Plain View Road south of Boulder, at Caribou Ranch and in Golden Gate State Park.
• Bottle gentians, gumweed and asters continue to bloom in the foothills.
Note to our readers:
The brown booby observed in Left Hand Canyon on June 22 and the subject of our July column was found a few days later near Nederland and taken to a rehab facility where it died in mid-August. The specimen is preserved at the Denver Museum of Nature and Science.
As golden aspen leaves fade and chlorophyll factories shut down, various understory plants adorn themselves in fall finery.
Golden currant leaves transmute to translucent crimson. Wild plums and chokecherries turn rosy, while wild roses flaunt yellow, orange and scarlet often on the same leaf. Sumacs, however, are the stars of the fall fashion show in the foothills.
Three native members of this family flourish in Boulder County: poison ivy (Toxicodendron rydbergii), three-leaf sumac (Rhus aromatic trilobata) and smooth sumac (R. glabra). Staghorn sumac (R. typhina) with velvety twigs is often cultivated in yards and sometimes escapes. Poison sumac (Toxicodendron vernix), widespread in the eastern United States, doesn’t occur here.
Poison ivy, however, is prolific especially in moist canyons. Its bright multi-colored leaves sometimes tempt unwary hikers to pick a bouquet. Remember the mnemonic: leaves of three, leave it be.
Three-leaf sumac also has three leaflets in shades of orange and salmon, but the berries are edible, and the leaves are pungently aromatic. Early settlers, who made a drink from the fruit, called it “lemonade bush.” Others call it “skunkbush.”
Smooth sumac, however, is what inspires us to take frequent pilgrimages along the South Mesa Trail and the Bluebell-Baird Trail to revel in the ruby red leaves that glow like stained glass when backlit by the low autumn sun. The dull red berries, high in vitamin C, are good survival food for robins, wild turkeys, mourning doves, small mammals and deer. We surmise, however, that wildlife must regard them as we regard broccoli since uneaten fruits persist on the branches into late spring. To us, the berries are slightly bitter with a faint lemony taste and cause a scratchy sensation in the throat.
Many Native American tribes have used both smooth and three-leaf sumac for tea, food and medicine since ancient times. The mummy of a woman found in the Ozarks and thought to be 20 to 30 centuries old had sumac berries in her stomach from her last meal.
Twigs were chewed to clean teeth; roots were made into a dye; stems were woven into baskets; and leaves were used to tan leather and for smoking. Various plant parts soothed menstrual pains, stopped bleeding from childbirth and from wounds, and cured ailments ranging from toothache to dysentery.
Almost all cultures weave stories to explain why leaves turn red. The immediate cause is that anthocyanin pigments form when high sugar concentrations react with proteins in the sap. Acidic sap produces bright reds; less acidic sap produces purplish hues. The most vivid colors occur when dry, sunny days are followed by cool nights.
In his Sept. 9 Daily Camera column, Jeff Mitton wondered about the reason behind autumn reds. Are the brilliant colors a warning that the leaves are unpalatable or do they serve as a type of sunscreen? There’s evidence for both hypotheses. Whatever the reason, we are simply grateful for the beauty of fall.
Ruth Carol Cushman and Stephen Jones are authors of “Wild Boulder County” and “The North American Prairie.”
