Wetlands probably provided some of the largest and relatively stable open habitats in the Northeast before forest clearing by Europeans. Unlike the understory of mature forests, wetlands have direct sun exposure throughout the growing season, which has significant implications for bee and flower diversity and abundance. Several wetland obligates (and many facultative wetland plants) are hosts to specialist bees. Pickerelweed (Pontederia cordata) and Water Lilies (Family Nymphaeaceae) are both reported as host plants for rare and uncommon bee species - the Pickerelweed Longhorn (Melissodes apicatus) and Water-lily Sweat Bee (Lasioglossum nelumbonis) respectively. A number of other uncommon to rare bees appear to be associated with wetlands, but not particular flowers. The Nelumbo Masked Bee (Hylaeus nelumbonis), Ocean Grove Metallic-Sweat bee (Lasioglossum oceanicum), and several others appear to be confined to wetlands. Wooded wetlands contain unique plant-bee associations—for example, Winterberry (Ilex verticillata) and (Colletes banksi) and Sheep Laurel (Kalmia angustifolia) and Kalmia Miner Bee (Andrena kalmiae), as well as abundant standing dead wood, which is an important nesting resource for many bees.