Originally a cultivated Asian import, but now as much a part of the American landscape as the dandelion, this weedy vine covers hillsides and infiltrates hedges throughout the city. It is remarkable for bearing two different colors of flower on the same stem. Children know that a drop of pure, sweet nectar may be carefully extracted from the base of the flower.
From Gray’s Manual: L. JAPONICA Thunb. (JAPANESE H.) Pubescent; leaves ovate or oblong, thickish, entire, short-petioled; peduncles rather short; bracts leaf-like, conspicuous; corolla white, pink, or yellow, the slender pubescent tube 2.5 cm. long; berries black. Escaped from cultivation and established in woods and thickets, Ct. to Fla. May-July. (Introd. from Asia.)
This was from the 1908 edition. The 1889 edition does not include Lonicera japonica, suggesting that it was not yet a common escape.
Although Gray says it blooms May through July, Japanese Honeysuckle will bloom sporadically throughout the year, and in Pittsburgh has a strong second season in the fall. This vine was blooming in a hedge in Beechview in early October.