Thursday, March 10, 2016

Cool Water Pipe in Agua Fria National Monument

Less than an hour north of Phoenix, cool water flows through Agua Fria National Monument in a deep canyon that winds from north to south through the desert landscape. Literature on this Monument, which was designated in 2000 by President bill Clinton, touts the importance of preserving prehistoric remains of Ancient Puebloans scattered throughout the windswept mesas.

We were surprised to find equally fascinating historic features on a recent hike through the canyon from Badger Spring trailhead to Sunset Point. Our guidebook, nor the maps and websites about the Monument, made no mention of the ~2-mile long 16" diameter pipeline that spans both sides of the canyon, crossing at one point via a timber brace perched on top of a granite pinnacle. Dozens of dry-stacked stone pillars support the pipe. Where there was not enough flat ground to work with, the pipe is suspended from cliffs by thick cables. This major engineering feat was accomplished for the benefit of providing water and power to the Richinbar Mine, which churned out gold and silver ore for more than 40 years, 1896-1937. The rusted remains of the pumps and a generating station are scattered below the rim near the old town site of Richinbar, currently a private inholding in the Monument, where about a hundred people made a living over a century ago.

Deep history is equally stunning. Strewn throughout the perennial stream, there are giant water-polished granite boulders filled with chunks of even older basalt.

The hike is a strenuous 10-mile boulder hopping adventure, but well worth the journey, especially on a warm day in the desert when wading and swimming in the many deep pools would be pure pleasure.

Friday, February 26, 2016

Wild Pennywort

A year ago, I wrote a short blog about Pennywort after sampling a drink I bought at a local Asian market. Pennywort showed up in my world again a few weeks ago during a visit to Tres Rios Wetlands in south Phoenix, where white pelicans and great blue herons are some of the many charismatic avian residents. To my surprise, one of the dominant plants floating around the edges of the ponds there is a close relative of the popular edible and medicinal Pennywort, also known as Gotu Kola in medicinal plant lore. Even more surprising, this species seems to be relatively new to Arizona! Here is what I've learned so far:

Hydrocotyle umbellata, commonly known as Manyflower Marsh Pennywort, is an aquatic emergent that grows in slow moving water, marshes, ponds and in some regions, lawns.  The plant is broadly established in southern California and in Texas, as well as throughout the southeastern and eastern states up to Nova Scotia, Canada. Large populations are growing in ditches and ponds at City of Phoenix Tres Rios Wetlands, a managed wetland project that uses treated effluent from the nearby 91st Avenue Wastewater Treatment Plant. The bright green floating mats of Pennywort leaves are clearly visible in recent images on Google Earth.

Previously collected specimens near this site and at the City of Phoenix Rio Salado Habitat Restoration Area demonstration wetlands, about ten miles east of Tres Rios, were incorrectly identified as Hydrocotyle verticillata, a closely related species. The two species are most easily distinguished by the the different kinds of flowering stalks: H. umbellata has "umbels," shaped like tiny umbrellas; H. verticillata has "verticels," which are vertically arranged on a slender spike. Both species have round, glossy, peltate (like a lily pad), leaves with ruffled edges. The plant spreads from submerged stems rooted in mud to create extensive floating mats along edges of ponds at Tres Rios wetlands.

No one is certain how it so recently appeared in Arizona, although it could have been here all along and nobody noticed. This is unlikely, however, since botanists have been scrutinizing the region for more than one hundred years. More likely, the plant may have been introduced as part of wetland restoration efforts along the Salt River. It is also possible that Pennywort was introduced by migratory birds that carry mud and seeds on their feet.

Keep your eyes peeled for other populations of this charismatic and opportunistic wetland species!
Like the Asian Pennywort, this one is also edible and may even increase your memory skills.