Tricyrtis macrantha ssp. macranthopsis
Fabulous Toad Lily with long arching almost hanging stems which have large broadly tubular rich yellow flowers sprinkled with red spotting in the interior. Yea verily. Perfect in a semi-shaded moist situation where it can spill, arch, hang and enchant. Ideally you would plant this on a humusy shoulder on the NE aspect of your sloping moss-covered cliff where it approaches the lower end of the pool which was formed in the creek by the waterfall at the pool's head and where it can catch the occasional errant waft of mist swirled by the intermittent gentle breeze underneath the high canopy of mature Acer palmatum. Lacking these very basic amenities, a simple moisture retentive woodsy soil in the shade will do quite nicely.