night blooming cactus
I wait for this cactus to bloom all year and most of the time I miss it. The lead up is torturous: buds plump up over a few weeks, from nothing to 8 inches long. Then they balloon out, till you think they can't get any larger before bursting open. Sometimes I get back to the house and find the spent bloom, collapsed in upon itself, a mere remnant of its former glory. But every once in a while, I get the full monty.
These flowers open at night and only last 1 day. Since the plant lives in PA and I'm in NYC half the time...well you see how that works. This year I've missed 3 blooms since the end of May but yesterday my patience was rewarded. The flower is at least 8 inches across and fragrant. Pistils and stamens are intricate and powdery, and the petals (and sepals!) are a study in different shades of white.
I'd grow this plant even if it didn't flower, because the structure is so interesting: classic cactus barrels with serious spikes. I like a plant that demands your respect, then rewards you for good behavior.