Gill-over-the-ground

This plant, which may be familiar to you, goes by many names: gill-over-the-ground, ground ivy, catsfoot, creeping charlie, etc.  It has very recognizable round, neatly scalloped leaves, and tubular lavender flowers.  Like many other members of the mint family, it spreads like a weed.

Growing near some creeping buttercups, on the western margin of the Lake, Central Park.

Common mallow

Common mallow.  These plants have cute dark leaves shaped like lily-pads and they like to grow right up on the border of sidewalks, on land that has been disturbed.  They are relatives of the European "marsh mallow" plant which - yes - was originally used to make real marshmallows.  You can use this plant to make them too, apparently, by boiling the leaves or seed pods in water until it is thick, mixing in sugar, then whipping the mixture up until it has a foamy texture and allowing spoonfuls of it to dry.  The leaves and wheel-shaped seedpods are also edible on their own.  Okra is in the mallow family, so it's unsurprising that both that vegetable and this plant have a mucilaginous texture when cooked.

The flowers can be white, or light pink-purple, or streaked with both colors, like this one.

Growing alongside the lower-level, east side path at about 122nd street in Morningside Park, Manhattan.

Red clover

Red clover.  They're bigger and usually grow taller than their white clover relatives, but otherwise look similar.  These flowers are edible.

West side of the Reservoir, Central Park.

Hairy beardtongue

Hairy beardtongue - it's easy to see that these guys are relatives of snapdragons.  They have little white open mouths.

North side of the Reservoir, Central Park.

Bittersweet nightshade

Bittersweet nightshade.  If you see this plant, leave it alone - like many nightshade relatives, it's very poisonous.  But very unique looking, with its weird curled-back petals:

Alongside a path just south of the North Woods in Central Park.

Slender blue flag

Slender blue flag, a type of purple iris.  These guys were too pretty not to take several pictures.

Growing around the eastern edges of Harlem meer, Central Park.

Common fleabane

Common fleabane - also called Philadelphia fleabane, or if it's white, daisy fleabane. 

In front of an empty building in Harlem.