Worth the read .... why natives ... Ephemerals

http://www.xerces.org/ephemerals-may-2016/

Spring ephemerals may be fleeting, but some native species host unique interactions with native pollen specialist bees. Pollen specialist bees associate with one host-plant family, a few related host-plant genera, or a single host-plant genus. For example:

• Spring beauty (Claytonia spp.) hosts the spring beauty mining bee (Andrena erigeniae)
• Trout lily (Erythronium spp.) hosts the trout lily mining bee (Andrena erythronii)
• Waterleaf (Hydrophyllum spp.) hosts the waterleaf mining bee (Andrena geranii)
• Bellwort (Uvularia spp.) hosts the rare bellwort mining bee (Andrena uvulariae)
Specialist bees of spring ephemerals are equally ephemeral: bees fleetingly fly and forage on above-ground host-plant flowers to provision below-ground nests, where bees rest quiet until successive springs.

Specialist bee and spring ephemeral associations can benefit both bees and flowers from better foraging efficacy, pollen digestibility, and pollination rates. However, spring ephemerals and hosted specialist bees are often rare or uncommon, and thereby susceptible to harm from habitat degradation, fragmentation, and loss, phenological mismatch, or inclement weather. Threats such as urbanization, timber harvesting, and climate change potentially imperil pollen specialists and spring ephemerals with population declines and extinctions.

Pollinator conservation projects in the temperate deciduous forests of the United States should prioritize actions that sustain abundant and diverse communities of native spring ephemeral host-plants. If spring ephemeral host-plants are already present in a given habitat, then they should be protected or enhanced. Protection from competing exotic plants, e.g., Norway maple (Acer platanoides), garlic mustard (Allaria petiolata), or lesser celandine (Ficaria verna), and browsing deer can support populations of spring ephemerals and their pollen specialist bees