[BSW] December 17, 2017 Annual Winter Solstice Field Trip and Hooley

Kathy Bilton kathy at fred.net
Thu Nov 30 11:02:21 CST 2017

at Mattawoman Wildlands at Chapman Forest, Charles County, MD

Sunday, December 17, 2017 - 10:00 am - 4:00 pm

Field trip co-sponsored by the Maryland Native Plant Society, Mattawoman 
Watershed Society, Potowmack Chapter of the Virginia Native Plant Society, 
and the Botanical Society of Washington.

Leaders: Rod Simmons, Jim Long, Alan Ford, and Robin Firth

Celebrate the beginning of the winter season at Mattawoman Wildlands at 
Chapman Forest (the vast section of Chapman Forest South abutting 
Mattawoman Wildlands) with its spectacular scenery and remarkable 
diversity of native plants, wildlife, and natural communities!  It has 
been 8 ½ years since we last visited this forest, for a jointly sponsored 
Summer Solstice Field Trip.

The south tributary of Chapman Forest South is a pristine, spring-fed 
stream that begins as a series of acidic seeps and Magnolia Bogs and flows 
through steep, forested ravines to Mattawoman Creek.  We will walk along 
the floodplain of this stream from near its convergence with Mattawoman 
Creek and proceed upstream a ways through gradual elevation changes to 
upland Oak-Heath Forest at the summit of the gravelly ridge.

This is a remote, wild area with a great diversity of wildlife (migratory 
fish spawn in the stream and bobcat have been observed, among many 
others).  This section of Chapman Forest is also a designated Important 
Bird Area (IBA).

In addition to discovering new things (we need to update our flora 
lists!), we should see a diversity of widely disparate flora, including 
the state-rare Deciduous Holly (Ilex decidua); Spinulose Wood Fern 
(Dryopteris carthusiana), montane disjunct Staghorn Clubmoss (Lycopodium 
clavatum) atop the ridge, and many species of evergreen ferns; White Bear 
Sedge (Carex albursina) and old-age Bitternut Hickory (Carya cordiformis) 
in outcrops of Shell-Marl Ravine Forest; large, old Willow Oak (Quercus 
phellos) and other bottomland species in Coastal Plain Oak Floodplain 
Swamps; American Mistletoe (Phoradendron leucarpum ssp. leucarpum); and a 
diversity of trees and shrubs.  Most of the vegetation here is typical of 
the Coastal Plain, but some sections of the south tributary pass through 
beds of calcareous marine sands and marl, which give rise to a distinctive 
flora with montane elements.

These ravines of calcareous sands and marl beds comprise a globally rare 
natural community called Shell-Marl Ravine Forest, coined by Harvard 
botanist M.L. Fernald in the 1930s after discovering similar forest 
communities in the Virginia tidewater region to the south.

This community type occurs only on the Coastal Plain where river bluffs 
and deep ravines over millennia have exposed underlying calcareous and 
glauconitic marine sands and marl beds deposited during the Paleocene, 
Eocene, and Miocene epochs when the area was a shallow sea at the western 
edge of the Atlantic Ocean.  The Brightseat and Aquia Formations are the 
prominent underlying strata in this section of Chapman Forest.

The combination of deep ravines, calcareous soils, and close proximity to 
the Potomac River has produced a remarkable flora predominately composed 
of species typical of the inner Piedmont and carbonate areas of the 
Appalachians that are otherwise rare to absent on the Coastal Plain, 
especially in association.  The forested section comprising most of the 
ravines and rolling valleys between Mount Aventine and Glymont at Chapman 
State Park (Chapman Forest North) is considered to be Maryland’s largest 
and finest example of this natural community type.

All of Chapman Forest is a fascinating and regionally unique meeting 
ground for plants with a primary range in the inner Piedmont and mountains 
and those of the southern Coastal Plain.

Field trip is free and open to non-members.  Registration is not required.

For ARMN members, this event will apply towards advanced training hours in 
botany, dendrology, forest ecology, and geology.

For more information on the natural communities of Chapman Forest, see 
Forest Communities and Geology of Washington and Vicinity, pp. 30-38, at 
the City of Alexandria Flora and Natural Communities webpage at 

For more information on Mattawoman Wildlands at Chapman Forest and 
Mattawoman Creek, see the excellent webpage at Mattawoman Watershed 
Society.  http://www.mattawomanwatershedsociety.org/

Bring: Wear sturdy shoes and bring lunch or snacks and water.  Most of the 
walk traverses rolling, fairly open forest and along some trails, though 
some steep grades and damp areas will occasionally be encountered.

Directions: Take Indian Head Highway (Rt. 210) south from Capital Beltway 
(495).  Proceed south on Rt. 210 for app. 15 miles.  Continue on Rt. 210 
to the Rt. 227 intersection at Bryans Road (McDonald's, Burger King, and 
shopping center on right and large CVS and builders supply will be on 
left) - don't take Prince George’s County versions of Rt. 227 many miles 
before this intersection!  Turn left at Rt. 227 and proceed south for 
approximately 3-4 miles.  Slow down as the road begins to descend down the 
big hill to Mattawoman Creek (Lamont's will be on the left about here) and 
be prepared to turn right just after the stream crossing at Buteaux 
Crossing and before the abandoned railroad tracks.  Parking area will be 
on the right at the railroad tracks.  We'll meet in this main parking lot.

For overflow parking, there is the also the area very near Mattawoman 
Creek opposite the parking lot above on the east side of Rt. 227, but it 
is small, often muddy, and dangerous to turn in and out of.  Parking along 
the road is not an option.

Carpooling is encouraged.  For those interested in carpooling to the field 
trip – or has room to provide a ride – we will send out a list of names, 
general location, and contact info closer to the time so that folks 
wishing transportation to the field trip can arrange something.  A number 
of folks in the Alexandria-Arlington-D.C. area will likely be looking for 
a ride to the site.

*In the event of heavy-steady snow, sleet, pouring rain, or icy, dangerous 
conditions of roads, the field trip will be cancelled.

( For an illustrated version of this as well as a 1998 article entitled 
Christmas Botany or How Reindeer Learned to Fly, write to Rod Simmons: 
Rod.Simmons at alexandriava.gov )

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