Plant of the Month: November 2020

I am in the throes of having my garden made over. This is because, when I was young, and even more ignorant than I am now: (1) I put too many shrubs in too close together; (2) I maximised planting space by giving myself stepping-stones from which to bend and gyrate as I tended the plot. Now that my bending and gyrating days are very firmly over, and the shrubs are too big and too entangled (did I mention that I’m a lousy pruner, too?) for me to get through/round, I have decided that I need to future-proof the garden against my encroaching old age.

So I have a design, drawn up by a very patient person who listened to me gibbering and gesticulating, and then transferred it all to paper. I have dug up and potted up all the plants I plan to keep (and my osteopath has benefited hugely), and I am hoping against hope that I will soon hear from the person who the design person recommended to carry out the work …

L. styraciflua ‘Lane Roberts’ in Cambridge University Botanic Garden

One of enduring my garden fantasies has been to have a Liquidambar, but my sane side told me I couldn’t, because I simply don’t have the space. However, yesterday, a kind person on Twitter informed me that there are two dwarf (and slow-growing) varieties available, and the fantasy has taken a firm shape and has a name (‘Oconee’).

A specimen of Liquidambar formosana ‘Monticola Group’ in Cambridge University Botanic Garden

The most familiar Liquidambar in the UK is, I imagine, L. styraciflua (named by Linnaeus, the two words meaning more or less the same thing: ‘liquid resin’ and ‘flow of gum’), which originates along the east coast of northern and central America. (There are other species, including L. acalycina (Chang’s sweetgum, from China), L. formosana (southern China, Taiwan, Korea, Thailand, Laos and Vietnam), and L. orientalis (a limited area of southern Turkey, plus, apparently, the Greek island of Rhodes).) The liquidambars used to be classed among the Hamamelidaceae (witch hazels), but have recently been reclassified into a family of their own, Altingiaceae. This name, which may have been coined either by the great and good John Lindley (1799–1865) or by a Russian botanist, Pavel Fedorovich Horaninov (1796–1865), was not accepted for most of the nineteenth and twentieth centuries, but at the molecular level it has recently been decided that liquidambars (and semiliquidambars) are now definitely a thing apart from mere hazels.

L. styraciflua, showing the scaly bark growth which probably gave rise to the name ‘alligator-wood’. (Credit: the Arnold Arboretum, Harvard University)

The common English name is ‘sweetgum’, but it is also known as just ‘gum’; or redgum, satin-walnut, hazel-pine, star-leaved gum, alligator-wood (because of the odd, scaly way in which the bark develops), and bilsted.  The ‘gum’ is the sweet sap which comes out of the trunk when it is cut; commercially, the gum is harvested by stripping and boiling the bark, and then pressing it. It can then be chewed, and was formerly a ‘gum base’ for some brands of chewing gum, though it seems less used today.

Francisco Hernández de Toledo, Four Books on the Nature and Virtues of the Plants and Animals Used for Medicine in New Spain, published in 1615

The tree first became known in Europe after the expedition of Francisco Hernández de Toledo (1514–87), the court physician of Philip II of Spain, who sent him in 1570 to the New World, to explore for medicinal plants and animals. He spent seven years in central America, studying both the natural history and the native people, but his magisterial writings were not published until 1615, long after his death, his manuscript having suffered all sorts of vicissitudes.

Hernández described a large tree producing a fragrant gum resembling liquid amber. Interestingly, there is possibly an earlier mention: in 1517, one Juan de Grijalva, nephew of the Spanish governor of Cuba, had an encounter with the Maya, during which he was offered hollow reeds filled with dried herbs and sweet-smelling liquid amber which, when lighted, diffused an agreeable odour. It is thought that this may have been liquidambar resin, which the Maya are known to have used medicinally.

The title page of an Italian edition of Hernández’s work, published in Rome in 1649 by a group of scholars who had acquired some of his manuscripts.

The first specimen of L. styraciflua to arrive in Europe was sent from Virginia in 1681 by John Banister (1650–92), born of ‘common folk’ in Gloucestershire, who apparently found a patron, because in 1667 he enrolled at Magdalen College, Oxford, proceeding B.A. and then M.A., and remained in the college, first as clerk and librarian and then as chaplain, until 1678. At this point, having clearly taken full advantage of the botanical opportunities at Oxford, he went to the New World.

He may have gone as a missionary rather than as a naturalist (though he did not receive an appointment as a minister in Virginia until 1689), but he was in the diocese of Henry Compton (1632–1713), bishop of London and the colonies in North America, an avid botanist who took advantage of his cure of souls covering such a large area to develop his grounds at Fulham Palace into one of the biggest botanic gardens of his day. Banister corresponded with Compton, and by 1679 he was sending specimens and species lists to Compton and other British botanists including Robert Morison at Oxford.

John Riley (?), Henry Compton, bishop of London; (Credit: The Queen’s College, Oxford)

Banister also supplied a list of Virginian plants, including liquidambar, to John Ray, who published them in volume 2 of the Historia plantarum (1688), with the comment that Banister was ‘eruditissimus vir et consummatissimus botanicus’; and the leaves and fruit are illustrated in the first part of Phytographia, by Leonard Plukenet (1641–1706), botanist and gardener to Queen Mary.

Ray’s entry for Liquidambar: as a medicine, it warms, strengthens, loosens and relieves pain
The liquidambar, with its seeds, is bottom left in this plate from Plukenet’s Phytographia

But the actual, live plant went to Compton, who planted it in his garden, along with Magnolia virginiana, Liriodendron (the tulip tree) and many other exotics. (Compton, or rather his gardener, George London (c. 1640–1714, a co-founder of the famous Brompton Nursery) also grew the first coffee tree in England in their stove house.)

Magnolia virginiana with a blue grosbeak, from Mark Catesby’s 1731 Natural History of Carolina

Sadly, John Banister, who had married and bought 1735 acres of land near the Appomatox river, died in 1692 when he was accidentally shot by a companion during a botanising expedition. He had sent back over 300 plant species and 100 insects, and lots of drawings of his discoveries. His collections and writings were brought back to England: some remain in Oxford, and others were acquired by Sir Hans Sloane and are now in the Natural History Museum. Banister is however probably best remembered in the United States not as a botanist but as a founder and trustee of the College of William and Mary in Williamsburg, the second oldest (after Harvard) university in the United States.

This one, in New Jersey, is rather bigger than the area of my garden … (Credit: Famartin)

Getting back to the tree, although it can grow up to 130 feet (c. 40 m) tall, the diameter of the trunk doesn’t expand proportionately (it rarely gets to more than 2–3 feet (1 m) in girth), but the timber is none the less prized as a hardwood – it is in this context that it takes the name satin-walnut. It is used for furniture-making and veneers (dyed black, it is a substitute for ebony). Much more recently, it has been discovered that the seeds contain shikimic acid, which (who knew?) is a vital component of flu vaccines …

The fruit of the liquidambar, known as the burr-ball or gumball

Incidentally, it is the seeds that have caused the tree to be banned as an ornamental in some American cities – when the fruit (‘gumball’ or ‘burr-ball’) falls on the pavement, it becomes a squishy slip-hazard for passers-by (see also Ginkgo biloba).

L. styraciflua ‘Lane Roberts’

But it is of course the tree’s ornamental qualities, rather than any commercial use, which have caused it to become so popular in the U.K., and to have so many hybrids as a result. There are four L. styraciflua ‘Lane Roberts’ @CUBotanicGarden, and one described as L. formosana Monticola Group. (There may be more, which I haven’t found yet.)

At this time of year, the colours are spectacular – right through the spectrum from green to deep purple – and I look forward to acquiring my own dwarf one in due course, so that I can enjoy the spectacle from the comfort of my own home …


This entry was posted in Biography, Botany, Cambridge, Exploration, Gardens, History, Natural history, Printing and Publishing and tagged , , , , , . Bookmark the permalink.

6 Responses to Plant of the Month: November 2020

  1. Leo JV says:

    Refreshing respite for me…after my daily dose of Samuel Pepys’ diaries. Wonders of the internet are welcomed more warmly when their arrival in my inbox is not gummed up with an unrelenting dose of politics.


  2. Leo JV says:

    Gum-pun was not intended!


  3. Rather good, though! What are you doing with Pepys?


    • Leo JV says:

      I am reading the diaries on a daily feed that is free for the asking…Takes a half-hour some days to read his entry as well as the notes of explanation provided by folks who have no thought (sometimes) for brevity.

      Liked by 1 person

  4. Pingback: Mr Kick and Mr Frankcom | Professor Hedgehog's Journal

  5. Pingback: Plant of the Month: July 2021 | Professor Hedgehog's Journal

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