The spring ephemerals are in bloom at Mountain Lakes Preserve. Their survival strategy is to emerge early, bloom, set seed and absorb solar energy for the next year. By the time the trees sprout leaves and cast a deep shade on the forest floor, these wildflowers are finishing up and getting ready to go dormant until the next spring.
The most common of these at Mountain Lakes is the spring beauty, which grows so abundantly along the driveway as to seem almost weedy.
Less common, surviving mostly in floodplains, is the beautiful trout lily.
Less common still (I've found a grand total of five of these in the whole preserve) are bloodroot, which actually keep their leaves into the summer.
Other spring ephemerals that you will be lucky to find in a few locations are windflower and toothwort.
The rarity of these wildflowers at Mountain Lakes is a legacy of the agricultural era, particularly the plow, which erased the soil's memory of past glories. Though the old fields eventually grew up in native trees, the spring flora don't have the capacity to quickly recolonize.
Browsing by deer has also played a role in suppressing wildflowers in Princeton's preserves, though the township's deer culling program is helping native species like the bloodroot to recover.