ARI SHAPIRO, HOST:
In parts of the South, there's a unique flower that grows in the middle of moving water. The Cahaba lily, also known as the shoals spider-lily, typically blooms for just a few weeks in late spring. And one of the world's largest populations is thought to be among the rocky shoals of Alabama. Mary Scott Hodgin of member station WBHM took a canoe trip to see the flowers up close.
UNIDENTIFIED PERSON #1: This one looks good there, Margaret (ph).
UNIDENTIFIED PERSON #2: They're all floating. They're all good.
MARY SCOTT HODGIN, BYLINE: I'm with about two dozen people, lined up along the banks of the Cahaba River just south of Birmingham. We buckle into life jackets and delicately climb into canoes.
WIL RAINER: Sweet. Does anybody not have a seat in a boat?
SCOTT HODGIN: Wil Rainer leads the trip. He's with the Cahaba River Society, a local nonprofit. Rainer says we're in for a treat.
RAINER: We are about to paddle down through the Cahaba River National Wildlife Refuge to go see the Cahaba lilies, a very, very cool flower that's pretty geologically remote.
SCOTT HODGIN: Cahaba lilies grow in only three states - Alabama, Georgia and South Carolina. They have big, white flowers with spider-like petals. Each flower blooms for just one day, usually between mid-May and mid-June. What's likely one of the world's largest clusters of Cahaba lilies is about a mile downstream from where we begin paddling.
(CROSSTALK)
SCOTT HODGIN: After a while, we see water bouncing off of rocks in the distance. The calm gives way to a rocky bottom and a field of white flowers surrounded by shallow water.
UNIDENTIFIED PERSON #2: They're pretty fast. They can get away. I think they can see our boat.
SCOTT HODGIN: We park our canoes and carefully walk along the slippery, smooth rocks. Scientist Randy Haddock gathers the group around a clump of the bright lilies.
(SOUNDBITE OF WATER SLOSHING)
RANDY HADDOCK: These seem to like this kind of habitat. What they're called is foliate rocks or flat rocks.
SCOTT HODGIN: Haddock has studied the Cahaba River for decades. He says the lily bulbs like to wedge into the rocks along the riverbed and nest there. The plants grow about three feet high. And when conditions are just right, lilies bloom one at a time. Haddock says the flowers emit a strong scent but not during the day.
HADDOCK: You don't get much aroma off these right now, but it's really in the evening hours and the early dark hours where these things - this place is amazing. The aroma is not overwhelming because it's pleasant.
SCOTT HODGIN: And that pleasant smell attracts a nighttime pollinator, the Sphinx moth, which is drawn to the lily's sweet nectar. Paddlers on the canoe trip, like Sam and Dale Foley, say the journey downriver is well worth it.
SAM FOLEY: Beautiful.
DALE FOLEY: Beautiful. I mean, this is...
S FOLEY: We've only ever seen them...
D FOLEY: That in where we drove in is all we saw before.
S FOLEY: ...You know, from a distance - never been out here, you know, walking around amongst them. So it's very nice.
SCOTT HODGIN: The Cahaba River is home to a lot of unique species, including endangered mussels and fish. The Cahaba lily is just one of the rarities found along the rocky riverbed. But to Randy Haddock, the flower is iconic.
HADDOCK: It's something that has just kind of become a symbol for the Cahaba, and it's just something that has inspired a lot of love and appreciation.
SCOTT HODGIN: Haddock says people are drawn to the lilies because they're beautiful. And they're a bit mysterious - large flowers growing in the middle of moving water, making an appearance just one day a year. For NPR News, I'm Mary Scott Hodgin in Birmingham.
(SOUNDBITE OF MUSIC) Transcript provided by NPR, Copyright NPR.