Plant Heritage Autumn 2008
Thymus Cultivars Update
I was appointed ICRA for Thymus at the end of 2007, provisional until the publication of the
Checklist, which I am currently compiling.
In the course of my quest for earliest known dates of publication of cultivar epithets I have been checking the literature;
nursery catalogues, periodicals, books, etc. and have uncovered yet more nomenclatural problems.
In my article in Plant Heritage in Spring 2003 I proposed that the pink flowered mat forming thyme, first listed in 1975 as
T. serpyllum 'Minimus', should be renamed T. serpyllum 'Minimalist,' as a Latin epithet is unacceptable after 1959.
Recent research with access to a greater number of catalogues has revealed the epithet 'Minimus' to be a printing error in the
1975 catalogue of RV Roger of Pickering, replacing the epithet 'Minus' used in their earlier catalogues.
This mistake was repeated in subsequent catalogues and copied by herb nurseries, wholesalers and garden centres,
but the older alpine nurseries still retained the 1924 epithet, 'Minor'.
Both Susie White of Chesters Walled Gardens and I have observed that thymes listed under both names appear to be identical.
This thyme will now be listed in the 2009 RHS Plant Finder as T. serpyllum 'Minor'.
In 1962 W E Th. Ingwersen Ltd. listed T. serpyllum 'Desborough', but did not list it again.
In 1973 this thyme was listed by RV Roger of Pickering as T. 'Desboro' and this spelling has been widely used
since and listed in the RHS Plant Finder.
However in early 2008 it became apparent that it had also been available in the wholesale trade under both spellings.
Although there would be a case for retaining the shorter spelling, in view of its long standing use, I propose that the original epithet
'Desborough' should remain as the accepted spelling, along with its specific name, as first listed by Ingwersens.
Arthur Shearing of Highdown Nursery raised two cultivars from T. camphoratus 'Derry' in 1999,
which are most likely to be hybrids with T. vulgaris.
Thymus 'Highdown' is normally listed without a specific epithet, although it does resemble T. camphoratus, but
T. camphoratus 'A Touch of Frost' has a growth habit more characteristic of T. vulgaris than its parent.
I therefore propose that it should now be known as T. 'A Touch of Frost'.
There are two prostrate thymes with long trailing stems, which for many years have been included in T.serpyllum;
T. serpyllum 'Lemon Curd' and T. serpyllum 'Rainbow Falls'.
However the former was first listed by Robinsons Gardens Ltd. of Eltham in 1952 as T. 'Lemon Curd'.
Before John Tuite opened his nursery, West Acre Gardens in Norfolk in 1994, he ran a wholesale nursery, Isla Nurseries, in Cambridgeshire.
In his 1987 catalogue he listed T. 'Rainbow Falls', a new variety selected by himself.
However ever since that date the majority of nurseries have incorrectly listed this thyme as T. serpyllum 'Rainbow Falls'.
Both these thymes should be listed without a specific epithet.
Neither thyme has the growth pattern characteristic of T. serpyllum.
As far as American Thymus cultivars are concerned, I have found that there is some confusion over the
correct identity of some of the older British cultivars.
I am very fortunate in having the assistance of Larry Hatch of the New Ornamentals Society (NOS).
He has been given a small grant to enable him to buy cultivars from nurseries to assess them and pass this information on to me,
including detailed digital images.
The vast majority of T. serpyllum 'Elfin' listed by American Nurseries is actually T. serpyllum 'Minor' and
pictures on websites show large mats of a compact creeping thyme.
Although T. serpyllum 'Annie Hall' is listed by many nurseries, the pictures on most websites show a bright pink flower,
rather than the flesh pink thyme first described by Clarence Elliott in 1924.
It is likely that a seedling has been confused with the original plant and this has been propagated in its stead.
Larry Hatch and I have therefore named this darker pink thyme T. serpyllum 'American Annie',
to distinguish it from the pale pink thyme collected by Annie Hall in Yorkshire.
Amongst the thymes obtained by Larry Hatch was an attractive creeping thyme with dark red stems and very hairy leaves,
incorrectly named T. serpyllum 'Elfin', which we have renamed T. 'Pewter Carpet'.
A large number of nurseries list a bushy thyme with silver variegated leaves, which is thyme-scented, rather than lemon and named
T. 'Argenteus', but distinct from T. vulgaris 'Silver Posie'. In order to avoid confusion with T. citriodorus 'Argenteus',
first listed by Backhouse of York in 1895 and which smells of lemon, Larry Hatch and I have named this thyme T. 'American Silver'.
In her 1982 thesis, A Study of the Taxa of Thymus Cultivated in the United States, Harriet Flannery
described T. vulgaris 'Narrow-Leaf French'.
This epithet had been listed by Kelsey as a common name in 1942, in Standardized Plant Names.
Within this cultivar epithet she included green, grey-green and grey
leaved, strongly aromatic thymes, defined as having revolute leaves and thymol aromatic oils.
She obtained these thymes from American nurseries, from Canada, Denmark, France and Germany and amongst the specimens
examined were English winter thyme, German winter thyme, French summer thyme and winter thyme and Greek thyme.
As this is too wide a variation to include under a single cultivar epithet, it had been considered
that a Narrow-Leaf French Group would be appropriate.
However although the creation of a group to cover these aromatic thymes would resolve this problem,
it could lead to more confusion as to which thymes should be included and which excluded.
The decision has therefore been made to treat all these highly aromatic thymes as synonyms of T. vulgaris,
but with the proviso that nurserymen may name selected seedlings or wild collected thymes within the species.
Thymus vulgaris is a native of the Mediterranean region and the Romans took it with them to northern Europe and in
due course the European settlers took it to North America. The most aromatic plants are from Spain, Italy, Greece and Israel,
in addition to those from southern France, making it confusing to include French in the cultivar epithet.
As far as leaf colour is concerned, the grey and grey-green leaved thymes tend to be the most aromatic and are from the Mediterranean region.
The dark green leaved thymes are more hardy than the grey and grey-green and are available in northern France, Germany and the UK.
Thymus vulgaris is not particularly hardy in northern England and needs regular propagation.
The cultivar T. vulgaris 'Deutsche Auslese' should be regarded as German winter thyme, which is a synonym of T. vulgaris.
The epithet 'Auslese' is invalid as it translates as "selected form".
French winter thyme is culinary thyme, sold to French housewives to grow on the kitchen window sill for winter use, under the name thym d'hiver.
The DeBaggio Herb Farm and Nursery of Chantilly in Virginia, have selected an aromatic thyme which they have named
T. vulgaris 'Narrow-Leaf French' and which they propagate from cuttings.
This will need a new cultivar name within T. vulgaris.
Michael Camphausen runs a small nursery near Bremen in Germany and has recently introduced two new thymes which he has raised.
Thymus 'Orangenteppich' is a 2005 seedling from T. 'Orange Spice' and possibly T. pulegioides 'Kurt',
first listed by Krauter-Simon of Efkebüll, near Langenhorn, in 2007.
The second is a dwarf white flowered seedling from T. vulgaris, which he has named Thymus vulgaris 'Weisser Zwerg'
and which he introduced in 2007. It may also be listed as T. vulgaris 'Weißer Zwerg'.
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