A small group of budding botanists met Sunday morning in Sibley Volcanic Regional Preserve to score the area for medicinal plants.

Tellur Fenner guided the group through the hilly park as part of his winter herb walk series. Fenner, 34, of Oakland, said his mission is to bring traditional herbal knowledge back to the mainstream.

Over about five hours, Fenner pointed out herbs to ease a range of aches and pains from stomach cramps and headaches to urinary tract infections, skin ailments and digestive maladies. The trip was a crash course in horticulture and herbal medicine with bits of anatomy and chemistry thrown in for good measure.

"It's unpopular, what I do as an herbalist," he said. "There's a lot of prejudice. People think, 'If you teach people about medicinal plants, they're going to go pick them all.'"

Fenner advocates identification and cultivation rather than foraging, citing many plants' somewhat fragile roles in the state's ecosystem. Before the walk, he made sure the group understood that picking on parkland is forbidden.

"This is about rediscovering lost knowledge," Fenner said. "So much of it has been lost already. What we do as ethnobotanists is to try to connect the fragments that still exist. We root through old literature, read the Native American ethnobotanies and try to bridge what we find with knowledge in Europe or traditional Chinese medicine. We experiment, try remedies on ourselves. If it works, we try it out on friends. That's the risk we have to take to try to bring this back to the surface."

Even before making it out of the parking lot, Fenner identified three notable plants: silk tassel, poison hemlock and manzanita. He went over the benefits and risks of each, explaining how their leaves and flowers could be used to identify them. Silk tassel, good to ease menstrual cramps, has long hanging blossoms, or catkins, that give the plant its name. Its leaves, he explained, appear in an opposite formation, directly across from each other on the stems.

"I'm not going to get too much into taxonomy," he assured the group. "You can take it so deep, it makes you want to kill yourself."

Fenner said he's been studying plants for 14 years and teaching for the past four. He grew up in the southeast, bouncing around Mississippi, Alabama and Texas living a "McDonald's lifestyle."

"I grew up on Main Street," he said. "I moved west as soon as I could, at 17, and fell in love with the landscape and culture."

Members of the group, nearly a dozen strong, came with various levels of experience. Some had taken horticulture classes at Merritt College or attended various plant-related workshops. One was studying Chinese medicine. Others just wanted an excuse for a weekend stroll.

Every 20 steps or so, Fenner stopped to explain the medicinal properties of another plant, challenging participants to identify its family or use. Oregon grape root, mint, mugwort and bay laurel were just a few of the specimens the group came across. Fenner explained which parts of the plant could be used for medicines; when to harvest; and whether to prepare tinctures, teas or just eat the plant outright.

As the group came across different varieties, he pulled glass vials of homemade tinctures from his bag, encouraging participants to sample the flavors from the dropper bottle. He made the tinctures using 95 percent ethyl alcohol and fresh plants, straining the resulting liquid into small glass jars.

"You can squeeze a few drops on your hand and lick it off. Or, if you're real careful, you can just do this," he said, holding the dropper above his mouth and squeezing gently. "Try not to lick all over it. People don't like that."

Fenner described the difference between pinnate leaves (feathery, compound leaves with leaflets branching off a main midrib) and palmate leaves (compound leaves where the leaflets are arranged like the fingers of a hand). The group also learned about plants heavy in essential oils, which are common in the mint, or Lamiaceae, family. Their pungent smell is a great way to identify oil-rich plants, Fenner said.

Cow parsnips, wild geranium and California figwort also lined the trail, not to mention poison oak, wild lettuce and willow trees vibrant with bright yellow catkins. Willow bark can be used like aspirin to reduce fevers and pains, though it doesn't have the drug's blood-thinning properties, Fenner said.

"Plants aren't drugs," he said. "They're biological factories in relation to physiology. They moderate themselves based on a person's consitution and health. Plants are magic, though I don't say that all that much because it tends to freak people out."

After a lunch break at the base of an old quarry, where dense clusters of newts lazed and mated in a seasonal pond, the group headed back down the trail. Fenner pointed out soap plants, clover, chickweed and cleaver as his students wrote and sketched his explainations in their notebooks.

Sylvia Sanchez, 31, of Oakland, said she couldn't think of a better way to spend a day. Sanchez is studying Chinese medicine and described herself as a nature enthusiast.

"I'm very much an advocate of sustainability and using local things that grow in our own climate," she said. "It's helpful to be able to understand what's growing around us. Usually I buy tinctures and supplements in stores. So this is kind of the next step for me, to learn how to identify and cultivate some of these herbs on my own."

Fenner said he's been happy, on a number of levels, to witness a growing demand for traditional knowledge about plants.

"This has to be done," he said, of training a new generation of enthusiasts and healers. "If we don't study, use and teach about plants that grow beneath our feet, this knowledge will be scattered to the wind. But, yeah, it's a struggle to have to make a living at this. You pretty much cross your fingers every month and hope you can pay the rent."

Fenner has herb walks coming up on Feb. 28 (Butano State Park) and March 7 (Samuel P. Taylor State Park). He'll teach a workshop on tincture making on Feb. 20 and 21. For more information, visit his Web site.

About Emilie Raguso

Emilie Raguso is a multimedia reporter in Oakland who focuses on issues of criminal justice, food and Oakland culture. She is passionate about social media, documentary photography and sustainable living. Her work has appeared on Salon and NPR, as well as in The Modesto Bee, Greater Good magazine and the East Bay Express. Write her at eraguso@gmail.com, follow her on Twitter (@emraguso) and see more of her work at http://raguso.us.