In the Spotlight: Glaucidium palmatum

Although known to Western horticulture since Siebold and Zaccarini first described it in 1845, Glaucidium palmatum was only recently rediscovered and made available in hort commerce. Like many other rare and unusual woodland perennials, Glaucidium is only available from a smattering of the most discriminating nursery owners and is usually accompanied by a steep price. For the true connoisseurs or collectors amongst us, I refer back to the one word that epitomized Mastercard in its day…. priceless!

 In midspring, robust mounds of bright green, lobed, palmate leaves are formed along stout stems to 0.6m.  These leaves, which appear to be many veined and crinkly grow to 15cm across, becoming progressively smaller and less lobed as they ascend the stem. Directly above the last leaf, atop the remaining inch or so of stem, slightly nodding, silken lavender flowers are produced in May and June. These flowers are solitary, terminal with four wavy. lobed, mauve to lilac tepals formed like petals to approximately 8cm across, with a delightful boss of many yellow stamens at their centre. It is a clump forming perennial with woody, rhizomatous rootstock.

Glaucidium palmatum is endemic to the mountainous regions of northern Honshu, Japan, in cool, moist humus rich soils, and is therefore one of those ‘holy grail’ plants that require strict edaphic requirements in order to be grown successfully! Where summers are hot and dry, water in abundance and position in full shade, in an area that is sheltered from the effects of desiccating winds. Slugs and snails pose a potential threat, especially when new growth is emerging in the Spring.

A rare white flowering form, G.palmatum ‘Album’ is also available, but is even more elusive in trade, making it the ultimate connoisseur’s coup de grace! As with other rare and unusual woodland gems., Glaucidium has ‘done’ the taxonomical circuit, being bounced between the families Paeoniaceae, Glaucidiaceae, and finally Ranunculaceae, where it remains today. From my own personal experience, it has always been a plant that has garnered interest, for the first two garden seasons for it’s breathtakingly beautiful, palmate foliage which, along the Shaded Walk, fit in perfectly with my other bold foliage combination, and this past year, it’s blooms surpassed even my own personal, fervent wishes! There was even a brief moment when I forgot about a somewhat ailing Meconopsis planted in it’s vicinity!