This sport of H. 'Halcyon' was registered by Peter Ruh of Ohio in 2005 on behalf of the originator, Roger and Ann Bowden of Devon, England . The medium size (18 inches high by 36 inches wide) plant has shiny, dark green foliage with thick substance. It bears pale lavender flowers in late July. This cultivar is part of the "Devon Series" of hostas.

According to The Hostapedia by Mark Zilis (2009), "...appears identical to 'Valerie's Vanity', 'Canadian Shield', and the other green leaved sports of 'Halcyon'."

The New Encyclopedia of Hostas by Diana Grenfell (2009) states: "Lovely in a cream stone container. Still the best-selling green-leaved hosta in Europe...Purple-dotted, dark green scapes."

Warren I. Pollock in The Hosta Journal (1994 Vol. 25 No. 2) states "H. 'Devon Green', a sport of blue-leaved 'Halcyon', has dark green leaves of the same distinct shape and characteristics as its parent. The petioles are purple spotted...H. 'Peridot' is a tissue culture sport of 'Halcyon' with dark-green, glossy leaves, described as being a little smaller than those of 'Halcyon'...Are 'Peridot' and 'Devon Green' the same hosta or sufficiently similar to be considered the same cultivar?...I'd like to see side-by-side trials."

An article about H. 'Canadian Shield', H. 'Devon Green', H. 'Peridot' and H. 'Valerie's Vanity' by Warren I. Pollock in The Hosta Journal (1997 Vol. 28 No. 1) states that, "These four hostas are mutations of 'Halcyon', arguably the best of the late Eric Smith's blue-leaved Tardiana Group...Are all four cultivars the same? I haven't seen any evidence they are different."

From The Hosta Journal, (2002 Vol. 33 No. 2), "...'Halcyon', 'Devon Green' and 'June'...are the same hosta but with different-colored leaves."

An article about the Halcyon Group by Peter Cross in The Hosta Journal (2004 Vol. 35 No.2) says, "...'Halcyon' is a first-generation member (TF 1 × 7) of the legendary Tardiana Group of hostas, which consists of hybrids of 'Tardiflora' × H. 'Elegans', produced in England by Eric Smith,  the master hybridizer of blue hostas, in the 1960s....Traditionally, sporting involves the cells in a section of a leaf (either margin or center) changing color...These sports simply lack the wax coating that makes the hosta leaves appear blue...I find it impossible to see any differences between these green sports..." Cross lists the all-green sports of 'Halcyon' including:

H. 'Devon Green' H. 'Valerie's Vanity' H. 'Canadian Shield' H. 'Peridot'

H. 'Emerald Coast' H. 'Grünspecht' H. 'Kryptonite'

An article by Warren I. Pollack in The Hosta Journal  (2020 Vol. 51 No. 1) titled Doppelgänger Hostas: Fancy Name for Look-alike Hostas, included a long list of hostas which various hostaphiles, published articles or other sources have indicated "look" the same. Some of these are, in fact, the same plant with two or more different names. Others are hostas that vary in some minor trait which is not immediately discernable to the casual observer such as seasonal color variations, bloom traits, ploidy, etc. So, as Warren mentions, hostaphiles may differ as to the plants listed but then, their opinions are based on visual observations and interpretations.

H. 'Canadian Shield', H. 'Devon Green', H. 'Grünspecht', H. 'Kryptonite', H. 'Peridot' and H. 'Vallerie's Vanity'.