Laburnum anagyroides Medik.

Laburnum anagyroides thrives even in cool, wet parts of the UK. Brockhole, Cumbria; 8 June 2013. Image Owen Johnson.

Foliage on Laburnum anagyroides at the Plantentuin Universiteit Gent, Belgium (16 June 2017). Image © Jan De Langhe - Arboretum Wespelaar.

Leaf variation on Laburnum anagyroides (Plantentuin Universiteit Gent, Belgium – 16 June 2017). Image © Jan De Langhe - Arboretum Wespelaar.

Scattered adpressed pubescence on Laburnum anagyroides (Plantentuin Universiteit Gent, Belgium – 16 June 2017). Image © Jan De Langhe - Arboretum Wespelaar.

Apiculate leaflet of Laburnum anagyroides (Plantentuin Universiteit Gent, Belgium – 16 June 2017). Image © Jan De Langhe - Arboretum Wespelaar.

Fertile branchlet of Laburnum anagyroides (Plantentuin Universiteit Gent, Belgium – 16 June 2017). Image © Jan De Langhe - Arboretum Wespelaar.

'Aureum'

Leaves golden yellow (but opening greenish). The combination of masses of yellow flowers and yellow leaves may suggest a gilded lily, but it would be unfair to imply that the foliage upstages the floral display, as it perhaps does in the case of the golden bean tree (Catalpa bignonioides ‘Aurea’). W.J. Bean (Bean 1981) observed that Golden Laburnum ‘affords one of the commonest instances showing the influence of scion on stock, for on grafted trees yellow-leaved shoots frequently appear considerably beneath the point of union’. However, patches of yellowish or patchily yellow leaves can be observed on examples of L. anagyroides which are very unlikely ever to have been planted as ‘Aureum’, more frequently perhaps than for any other tree species, and are presumably stress-induced or pathogenic. ‘Aureum’, meanwhile, is known to revert (Edwards & Marshall 2019).

‘Aureum’ is very occasionally treated as a cultivar of L. alpinum, as at https://jardin-florilege.eu/en/encyclopedie/laburnum-alpinum-aureum. Like most Laburnum cultivars, it is now certainly rare in the UK, but still grows in the collections at Kew and at Thorp Perrow in Yorkshire.

The name ‘Vossii Goldleaf’ occurs occasionally in horticultural literature and is usually assumed to be a clone of L. × watereri. However, Laurence Hatch’s reference to a specimen at Thorp Perrow (Hatch 2024) should probably be taken to imply that this was merely an illegitimate renaming of L. anagyoides ‘Aureum’, due to some nursery that wanted its clientele to assume that the flowers were as good as those of L. × watereri ‘Vossii’, the clone which is generally described as bearing the longest racemes of any laburnum.

Flowers and golden leaves on an old plant of Laburnum anagyroides 'Aureum' at Crathes Castle, Aberdeenshire. Sadly this tree blew down the year after this photograph was taken in 2007. Image Owen Johnson.

'Autumnale'

A group of old selections that continue to flower sparingly through the season. The description of L. anagyroides ‘Autumnale’ in Edwards & Marshall 2019 presumably derives from the form still grown at Sir Harold Hillier Gardens, which flowers ‘sometimes again in autumn’. Another tree nearing the end of its life at Thorp Perrow Arboretum, Yorkshire, UK (Tree Register 2024) has not been checked to confirm that it is not really a representative of a comparable selection of L. alpinum (q.v.).

'Carlieri'

W.J. Bean’s description of this variant (Bean 1981) is now merely of historic interest – no examples seem to have been cultivated more recently – and needs little updating:

There seems to be some confusion over the correct use of this name. [Oskar von] Kirchner’s original description, from a plant growing in the Muskau Arboretum [Muskauer Park], states that the variety had very small grey-green leaves and was free-flowering, with long densely flowered racemes. Many of the trees at Muskau were supplied by James Booth and Sons of Hamburg, and there is a specimen in the Kew Herbarium from a tree received from that firm in 1872, which agrees well with Kirchner’s description. The leaflets are remarkably small, [11–25 mm long × 3–4 mm wide], and the racemes [are only 12–25 cm long]. Another specimen, obviously of the same variety, was taken from a tree received at Kew from Späth in 1903. But the laburnum described by [Camillo] Schneider as L. anagyroides var. carlieri sounds quite different, having very short, almost erect racemes (Schneider 1912).

'Columnaris'

Described by Laurence Hatch as a densely columnar plant of very slow growth (Hatch 2024). The latinate name implies this cultivar was extant by 1959. A ‘Columnaris’ was also listed under L. × watereri in the 1987–8 catalogue of Belcher Nursery in Oregon (Jacobson 1996).

'Erect'

A fastigiate seedling found by Alf Alford at Hilliers Eastleigh Nursery in 1964 (Edwards & Marshall 2019), and still commercially available (Royal Horticultural Society 2024). It is grown at the Sir Harold Hillier Gardens, but has proved short-lived there (Tree Register 2024).

f. pendulum (Bosse) Rehder

Strongly weeping forms of Common Laburnum seem to arise quite frequently, so it is probably most appropriate to treat such plants as a forma. They have been known for a long time with pendulum being mentioned by Loudon (1838). W.J. Bean described a variant from the early 20th century as ‘very graceful in habit’ (Bean 1981). Some contemporary offerings weep stiffly from a high graft, and in parts of North America these are grown as commonly as the type (Hatch 2024).

There is also likely to be confusion with weeping selections of L. alpinum (q.v.), and possibly of L. × watereri. ‘Vossii Pendulum’ is claimed by Laurence Hatch (Hatch 2024) to be a weeping variant of L. × watereri ‘Vossii’, but the analogy of ‘Vossii Goldleaf’ (q.v. under L. anagyroides ‘Aureum’) makes it seem likely that some unscrupulous nursery wanted its customers to think that its stock of weeping laburnums would carry flowers as spectacular as those of L. × watereri ‘Vossii’. However, ‘Vossii Pendulum’ is still sold (as a clone of L. × watereri) by Chew Valley Trees in the UK in 2024 (Royal Horticultural Society 2024).

Bean's description of Laburnum anagyroides 'Pendulum' as 'very graceful' is probably subject to scions being top grafted on a tall stem. This somewhat dumpy example grows in the otherwise exquisite garden at Dundonnell in the north west highlands of Scotland. 4 June 2024. Image Tom Christian.

This gracefully weeping and ungrafted old Laburnum anagyroides, in an out-of-the-way corner of Bedgebury Forest, Kent, UK, is rather unlikely to have been planted as f. pendulum. August 2024. Image Owen Johnson.

Another Laburnum anagyroides of weeping habit in Silton churchyard, Wiltshire, UK, in summer 2006. In this case the main stem has collapsed, adding to the tree's non-aspirational appearance. It is likely to have been admired in passing by numbers of dendrologists on their way to Wyndham's Oak, a gigantic and ancient tree which grows just east of the churchyard. Image Owen Johnson.

'Involutum'

A group of clones with twisted or bullate leaves: ‘Involutum’ was listed by James Booth of Hamburg in 1838 and var. bullatum was described from France in 1847 (Bean 1981). The Czech resource Dendrologie Online 2024 lists f. monstrosum and f. crispum as additional synonyms, while ‘Cristatum’ was offered by the Dutch nurseryman C. de Vos, who described his plant as slightly less hardy than the type and holding its leaves close to the branch (de Vos 1887). None of these variants are likely to remain in cultivation.

'Layr'

One of very few Laburnum selections to have been made since the 1960s, YELLOW ROCKET arose in Hungary and is described as an improvement on older, fastigiate selections such as ‘Erect’ in terms of habit and flower production (Breederplants 2024). However, fastigiate trees tend to become less graceful as they age and only young examples of YELLOW ROCKET are known so far.

Curiously, a few authorities (such as Breederplants 2024) treat LAYR as the sale name (with Plant Breeders’ Rights) and ‘Yellow Rocket’ as the cultivar name.

'Quercifolium'

A curiosity whose leaflets are shallowly lobed, a little like an oak’s, and which can also be carried in fives. The main leaf-stalk is sometimes winged, and the petals are toothed, the wings with slender lobes on the upper sides (Bean 1981; Edwards & Marshall 2019). An old tree, much reverted, survives in the laburnum collection at Thorp Perrow, Yorkshire, UK (Tree Register 2024), and the cultivar is still offered by Bluebell Nursery (Bluebell Arboretum and Nursery 2024). But as the American dendrologist Michael Dirr has commented, you need to get within inches of this plant to notice what is special about it (Dirr 2009).

The curious, unlikely leaves of Laburnum anagyroides 'Quercifolium'. Bluebell Arboretum, Derbyshire, UK. 11 June 2024. Image Tom Christian.

Leaf undersides on Laburnum anagyroides 'Quercifolium'. Bluebell Arboretum, Derbyshire, UK. 11 June 2024. Image Tom Christian.

'Sessilifolium'

Described by Bean (1981) as a sport with ‘leaves crowded, almost stalkless, their bases thus being brought close to the branchlet. A curiosity of no garden value, the branches having a stiff, stunted appearance; not free-flowering.’

'Sunspire'

A fastigiate selection with short branches and short, dense racemes of flowers (Dirr 2009); ‘Sunspire’ remains quite widely available in Europe. Royal Horticultural Society 2024, perhaps uniquely, treats it as a cultivar not of L. anagyroides but of L. × watereri.