Sometimes you grow a plant for three years, and it finally decides to bloom just as you are going out of town for a week.
As we were rushing around making last minute preparations to leave for the airport, I noticed these buds emerging from a northern spiderlily bulb (Hymenocallis occidentalis).
Although Hymenocallis are tough, long lived bulbs, their flowers subscribe to the philosophy “live fast, die young.” I was convinced that by the time we got home, I’d find nothing but a wilting inflorescence topped by shriveled, brownish tissue. A cold front that dropped the temperature below 90 F may have helped to prolong the life of the flowers, because when we arrived home yesterday I found that the blooms weren’t completely senescent. They had sustained significant damage from heavy rain, but I think you can still appreciate the fireworks-like quality of the mass of spidery flowers.
The genus Hymenocallis ranges from the southeastern United States to northern South America, and as its common name suggests, H. occidentalis is the northernmost species, growing from northern Florida to eastern Texas and up the Mississippi valley as far as southern Illinois and Indiana. H. occidentalis often grows in moist woodland, so it is probably one of the best members of the genus for garden cultivation, particularly in the north. Other U.S. species grow in wetlands or rivers as emergent water plants and would probably require a pond or bog garden.
Some of the Mexican or Caribbean species (e.g. H. ‘Tropical Giant’) grow well in regular garden conditions and are fairly hardy if planted deep and mulched well. In my garden, I also grow the Mexican species H. pimana and H. ‘New Lion’, a plant of uncertain identity (species or hybrid?) originating from a garden in somewhere in Nuevo León, Mexico. Because its flowers open sequentially, it blooms over a longer period than H. occidentalis but is not so spectacular.
I also grow H. traubii, a miniature wetland species native to Florida, in a pot that I sit in a tray of water. It seems to produce only two flowers per inflorescence, but they are large for the size of the plant.
Moth-pollinated Hymenocallis flowers are fragrant and, as you can see from these photos, invariably white. The genus gets its scientific name, which means ‘beautiful membrane’, from the tissue that connects the base of the stamens. This cup varies in size from species to species and is shared by Ismene, a genus of closely related bulbs from Peru. Ismene and Hymenocallis are distinguished primarily by their foliage. In Hymenocallis, the leaves are arranged in a simple rosette, while in Ismene, the leaf bases are clasped together to form a pseudostem. Also, Hymenocallis flowers tend to face up, while Ismene flowers are held horizontally, facing out.
Two old primary hybrids of Ismene are readily available from bulb vendors in the Spring: Ismene ‘Sulphur Queen’ and Ismene x festalis. Both are large plants that grow well in 5-gallon or larger nursery pots, and I. x festalis, at least, is reliably hardy in my garden. I have been growing I. ‘Sulphur Queen’ in a pot, but I think by the end of this year I’ll finally have enough bulbs to try a few in the ground.
Some I. x festalis clones have a tendency to split, producing many small bulbs, instead of flowering. It’s worth seeking out I. x festalis ‘Zwanenburg’, which is a reliable bloomer.
Update: August 20, 2017
One week after the first H. occidentalis bulb bloomed, a second is flowering. I planted this bulb in a more shady spot, because I wasn’t sure how much sun H. occidentalis needed. As you can see, it has fewer flowers than the one planted in full sun, but I was able to get a picture of fresh, undamaged blooms. My impression is that H. occidentalis has larger flowers than my other Hymenocallis, but I’ll need to make measurements of other plants next year to be sure