Choisyas

November, 2020

While the year 2020 dishes up one disaster after another, many of us have been seeking consolation in the refuge of public parks and greenspaces as well as in the shelter of our own gardens. Surveying my surroundings this Thanksgiving season, I find myself especially grateful for tried and true evergreens that brighten the borders in these darkening days. At the moment my eye is drawn to a golden shrub that has graced a corner of my garden for more than 20 years with its lustrous, even luscious lemon-hued leaves and fragrant, star-shaped ivory flowers: Choisya ternata ‘Lich’ SUNDANCE, commonly called golden Mexican orange-blossom.

What’s not to admire about an easy-going, easy growing shrub that gives so much and requires so little in return? Among its major attributes are three bloom cycles a year (in late spring, midsummer and autumn—my specimen is coming into full flush again as I write this in late November), fragrant foliage and flowers (see note below)¹, drought tolerance once established, ability to thrive in a tough neighborhood (mine is undaunted by two nearby eucalyptus behemoths) and a hale and hearty response to hard pruning if one needs to shape it or restrict its spread.

This chartreuse charmer has a fascinating back story to unearth. Let’s dig into it, shall we? As the common name attests, Choisya ternata ² is native to Mexico, probably to the mountains surrounding Veracruz. Rare in the wild, it seldom sets seed and apparently had long been in cultivation in its land of origin when collected around 1804 by the demigod duo of Alexander von Humboldt and Aimé Bonpland near the end of their extensive, epoch-altering exploration of the Western Hemisphere. It was one of around 6000 specimens (a mind-boggling 2000 of which were new to European botanists) they brought back to Paris to be catalogued, a task carried out in great part by Humboldt’s brilliant young assistant, Carl Sigismund Kunth. They named the new genus to honor the eminent Swiss botanist Jacques-Denys Choisy ³. In subsequent decades other botanists located and described half a dozen additional species growing as far north as Texas, New Mexico and Arizona. More recently some of these have been crossed with C. ternata to produce gorgeous hybrids such as ‘Aztec Pearl’ and ‘Apple Blossom’, among others.

*Choisya ternata* ‘Lich’ SUNDANCE flowers (left) and close-up

Our golden Choisya ⁴ is not a hybrid, but a selection of the original species discovered by chance about 40 years ago, then painstakingly nurtured, and finally marketed through the diligence of British nurseryman extraordinaire and Victoria Medal of Honor winner ⁵ Peter Catt. Here’s the scoop: While at work in 1978 at his Liss Forest Nursery (Hampshire, England) Catt spotted a variegated sport on a lower branch of a Choisya ternata from which he was taking cuttings. He rooted it, and as it grew it lost its variegation but developed into a stable gold-leafed plant, which he propagated and then trademarked with the legal name Choisya ternata ‘Lich’ SUNDANCE ⁶. This was among the first plants in Britain to get PBR (Plant Breeder’s Rights) protection, a designation like a plant patent. The glowing golden beauty had its debutante ball at the 1986 Chelsea Flower Show; it soon took the gardening world by storm and has since become a bit of a botanical cliché, at least in Great Britain. In recent years SUNDANCE has been crossed with C. arizonica cultivars to produce hotshot dazzlers such as ‘Goldfingers’, ‘Gold Star’ and ‘Aztec Gold’. The ubiquity of the original doesn’t stop me from loving it, however. At this point it is an old friend I continue to cherish. Wishing you all a Happy Thanksgiving, I’ll see you in December.

Horticulturally yours,

Daniel

Notes:

Although most references to Choisya speak of the orange-blossom fragrance of the flowers, to me their aroma is heavier, almost earthy, redolent of almond extract. The foliage boasts a pronounced odor as well, albeit a pungent one.
The specific epithet ternata is refreshingly straightforward, meaning “in clusters of three,” a reference to its foliar pattern. Occasionally, however, an overachieving node might produce four or even five leaves.
For botanical names that honor an actual human, it’s good manners to articulate them in a way that person would have recognized. In respect of Monsieur Choisy, we should endeavor to pronounce the genus like this: SCHWAH-zee-ah.
Choisya belongs to Rutaceae, the citrus or rue family. As such, the common term Mexican orange isn’t that far off the mark, unlike the common moniker “mock-orange” for Philadelphus species, which belong to the totally unrelated family Hydrangeaceae.
The Victoria Medal of Honor is the highest award given by the Royal Horticultural Society. In recognition of the eponymous queen’s 63-year reign, there can be no more than 63 living recipients at any time. Therefore, the award sometimes skips a year. In addition to Peter Catt, other VMH awardees familiar to us include Fergus Garrett, Penelope Hobhouse and Roy Lancaster, as well as the late David Austin, Rosemary Verey, and Christopher Lloyd.
Ever wonder why some fancy plants (particularly hybrid roses) seem to have two cultivar names? The first one, in single quotations and often of inscrutable origin, is the cultivar’s legal name—for patent purposes; the second, which should be (but often isn’t) in all capital letters is the trade or marketing name. That’s what’s going on with Choisya ternata ‘Lich’ SUNDANCE, although no one actually calls it ‘Lich’. I’m going out on a limb and guessing that the legal name’s first two letters (Li-) refer to Peter Catt’s nursery, Liss Forest, and the last two (-ch) refer to the genus Choisya. If you know better, please inform me.