Multiflora Rose,  Rosa multiflora
Rosaceae or Rose Family
 

A moderate sized shrub, about 3 feet tall, thorny.  Compound leaves have 5-9 leaflets, and the bases of the leafstalks are deeply fringed.  Flowers are numerous, with 5 white petals, widest at the tip, and yellow stamens.  Blooms in summer.

Alien, formerly common in cultivation and now escaped to waste places, roadsides and thickets.  In Wildwood, mostly along Wildwood Drive. 

Easily recognized as a many-flowered white rose.  Carolina or pasture rose (Rosa carolina) is a low plant, with fewer, larger, pink flowers.  Some brambles (Rubus species) have similar flowers, but have leaves with fewer leaflets and flowers with petals widest in the middle.