Of the three species of trillium growing at the Marie Butler Leven Preserve, the large-flowered trillium is by far the most common.

In April, patches of large-flowered trillium can be seen in bloom on the forested hillside that slopes towards the Preserve's seasonal pool.

A view of the entire large-flowered trillium colony in bloom. We are gradually weeding the invasives out of this area but it's slow going. We have to be careful not to disturb these and the other native herbs on this hillside.

The purple trillium is present at the Preserve but not common. The flowers of this species smell awful. They are pollinated by flies.

The yellow trillium is also present at the Preserve, in small numbers. Its flowers smell like lemon.

Squirrel corn, a member of the poppy family, occurs here and there on the same wooded slope where the large-flowered trillium grows.

Cut-leaved toothwort, another denizen of moist woodlands in the mid-Atlantic.

Virginia bluebells (pale blue flowers) growing with large-flowered trillium.

Wild blue phox grows in patches on the slopes that drain into the Preserve's pool.

Common periwinkle, an invasive alien garden escape, surrounds a patch of phlox. We are gradually removing the Preserve's invasive groundcover. We have to go slowly to avoid erosion and to minimize disturbance to the natives.

The distinctive leaves of the American chestnut, once a common tree in the eastern United States but now suppressed by an alien fungal pathogen (the "chestnut blight"). The blight cannot kill the chestnut's roots, which continue to send up stump sprouts, which the blight eventually does kill. Chestnut stump sprouts can be found at the Preserve, as in many eastern forests.

A pawpaw flower. Pawpaw is a moist-soil understory tree. It can be found along the path leading down towards the pool. A member of the custard-apple family, pawpaw bears a greenish-yellow fruit that tastes a little like pineapple.

The small three-stemmed tree growing on the bank of the gorge is a sweetbay magnolia. Although many magnolias are grown in the DC-area, sweetbay is among the few that are native to the region. There is a sweetbay colony at the Preserve; this is the largest specimen.

Fertilized flowers on a witch-hazel. This is one of the plants in the witch-hazel bank that we planted just south of the Pollinator Garden. Witch-hazel is a large shrub with a peculiar reproductive schedule: It blooms in fall and winter.

Tickseed sunflower, a plant of wet meadows and swamps, growing in the Preserve's Native Pollinator Garden (and, of course, planted there by us). Note the bumblebee—a native pollinator!

Swamp milkweed, also in our Native Pollinator Garden, visited by another native pollinator: a monarch butterfly.