Hypericum punctatum

That's right, Ellery. The quiz plant was Hypericum punctatum. With flowers or even leaves, this would have been a much easier quiz, as H. punctatum and H. perforatum are very easy to tell apart during the growing season. Outside of the growing season, there aren't as many characters to use to distinguish the two. H. perforatum would have a more angled stem formed by decurrent leaf bases. Also, H. perforatum is more woody/shrubby than H. punctatum. This character isn't as obvious from the photo I posted, but in seeing the plant in person this is more obvious. Finally, the sepals of H. punctatum are blunt to acute, while those of H. perforatum are linear-lanceolate and attenuate.

The genus name Hypericum comes from the ancient Greek name Hypericon, which was derived from the word meaning "over a picture." Flowers were often collected and placed above pictures in the house to ward off evil spirits at Walpurgisnacht, the midsummer festival associated with the summer solstice that later became known as the feast of St. John. The specific epithet, punctatum, refers to the black and transparent dots on the leaves and petals.

Nice job, Ellery. And good guesses, Keith.