A showy terrestrial orchid

There's a lovely orchid flowering right now in the Garden, in one of the perennial beds. It's a terrestrial orchid from Asia, Bletilla striata, native to grassy foothills in China and Japan. Hardy to zone 6 or so, its ability to grow in the garden (in well-drained rich soil) makes it a nice addition to a mid-spring border. The species is a nice rose-pink -- this white form is 'Alba.'

The flowers are long-lasting, and plants spread nicely from corm-like pseudobulbs if conditions are right.