Buxus sempervirens in the Harris Gardens, Reading University ©S.Medcalf2017

Buxaceae at Whiteknights

There’s a man buried vertically, head downwards on a hillside called Box Hill near Dorking in Surrey. You could say he was off his head when he died in 1800. No, maybe on his head…

“the world is topsy turvy, and I’ll be the right way in the end” (Major Peter  Labellière)

His reasons have a certain resonance in our current topsy turvy, ‘post-truth’ era…

Despite being buried on Box Hill, I doubt his coffin – if he had one of course, was made of boxwood. This timber was far too precious. It was used for making crafted items such as bobbins for lace-making, woodcuts for printing and musical instruments because it has a wonderfully dense and fine end grain which makes it ideal for wood-turning. In the 19^th Century it was much in demand for its timber which led to its demise in many parts of Europe as it is a slow-growing tree.

Boxwood bobbins. More details on uses of Box can be found on the Chilterns AONB Box Woodlands Project pages. Credit:The Chilterns Conservation Board

“European Boxwood logs and Paulhahn from European boxwood” Permission from F. Frydrysiak, Instrument maker. Slow-growing boxwood is a favoured timber for instrument makers because it can be turned with precision with good and sharp tools without the need to finish off with sandpaper. Read more here

In 1800 the Box tree (Buxus sempervirens) would have been a familiar sight in many places with chalky soil. In his ‘Remarks on Forest Scenery’ (1791), William Gilpin, who famously introduced into English cultural debate the word ‘picturesque’ (which literally means ‘in the manner of a picture’) which incorporated the sublime and wild in artist’s landscapes, described the beauty of the twisted look of box stands on Box Hill as picturesque ‘with their exposed roots and irregular shapes’. If you are lucky enough to stumble upon some box trees today, it could well be that it is your nose that alerts you to their presence rather than your eyes – for the smell of B. sempervirens has been likened to the delightful smell of, well, tomcats. Nice.

Whiteknights campus is certainly a great place for exploring Buxaceae perfumery….. If you have a penchant for checking out the delights of B. sempervirens for yourself there is a hedge of it where the Harris Gardens borders the Wilderness just beyond the Autumn Border.  It is marked as ‘Ecozone 1’ in the handy guide found here .

The campus species list also mentions it being ‘sporadic within the Wilderness’.

An unruly box hedge runs along the border between the Harris Garden and the Wilderness, Whiteknights, Reading ©S.Medcalf2017

Wandering about the Whiteknights campus around Valentine’s Day, your nose might catch the fragrance of love from another plant in the Buxaceae family. It took me a while to guess where the intoxicating, beautiful scent came from when I first arrived on campus because the flowers are fairly inconspicuous. But once you have spotted it there is simply no mistaking the wonderful genus Sarcococca much favoured as a hedging plant nearly everywhere dotted around campus buildings. It also wafts you in and out of Whiteknights at the Pepper Lane entrance. On the subject of hedges, box (Buxus) has of course been used extensively as the classic, clipped bush of choice most associated with French chateaux and formal baroque-style gardens.

Sarcococca at the Pepper Lane entrance to Whiteknights campus  ©S.Medcalf2017

More can be found on the horticultural history of the genus Sarcococca in British gardening in this Guardian article by Robbie Blackhall-Miles (more on his work at www.fossilplants.co.uk.) He tells us that the first Sarcococca species to arrive in our gardens was S. hookeriana from the Himalayas thanks to Sir Joseph Hooker who discovered it in about 1825; since then other species such as S. wallichii (Nepal), S. orientalis (Christmas Box, China) and S. confusa (Sweet Box, native probably to China).

From the point of view of their evolutionary relationships and taxonomy, the box family Buxaceae sits within the Order Buxales (Angiosperm Phylogeny Group III & IV) as a core eudicot. This means it probably started evolving about 100 million years ago (Buxales, Stevens, P.F. Angiosperm Phylogeny Group (www.mobot.org).

Its distribution is widespread (Buxus) but scattered from more or less temperate zones to the tropics (Sarcococca is mostly from East Asia).  Resolution of the relationships between species that are found today can only come about through molecular studies of their DNA – and piecing together the incomplete clues this miracle of evolution has left for us here on earth. What is clear so far, the box family has four main groups comprising of 5 (possibly 7) genera in total and c.100-120 species. They are evergreen and woody. Other genera in this family, in addition to the familiar Buxus and Sarcococca, include Styloceras, Notobuxus, Pachysandra,  Didymeles and Haptanthus. The first five of these are worldwide genera found from the temperate areas to the tropics and the first three are found in the Neotropics (see a useful webpage by Egon Köhler explains more at Kew Neotropikey) and the last two have only recently been added to the family, but make it paraphyletic.

Pachysandra terminalis, Japan. Kew Gardens ©S.Medcalf2017

Buxus and Sarcococca are found on Whiteknights campus. So let’s have a look at the flowers and leaves of these two genera in this family that grow here in Reading.

©S.Medcalf2017

Buxaceae species generally have evergreen leathery leaves; these are arranged along the stems as opposite, decussate in Buxus and spirally in Sarcococca.  They have separate male and female flowers on the same plant (which is termed ‘monoecious’). These flowers are actinomorphic, small, and fairly inconspicuous (to the eye, if not to the nose….) and are aggregated in clusters in leaf axils Functionally male flowers have four stamens and are in these leaf axils and in terminal flower clusters. Functionally female flowers are only found terminally and have three styles, surrounded by a cluster of male flowers. The small green petal-like structures (whiter and more conspicuous in Sarcococca) are called ‘tepals’ and look star-shaped in the female flower. The ovary has three carpels which is far more obvious in the fruit of Buxus, which are dry capsules compared to Sarcococca which has the obvious black berries.

So next time you are asked what links the neat lines of a formal garden with irregular twisted trees or perhaps a sweet fragrance with the smell of cat wee, it has to be the box family.

References

Balthazar, M. von & Endress, P.K. 2002. Reproductive structures and systematics of Buxaceae. Bot. J. Linn. Soc. 140:193-228.

Blackhall-Miles, Robbie. 2014.  Sweet box: heaven-scent Sarcococcas. Guardian newspaper. https://www.theguardian.com/lifeandstyle/gardening-blog/2014/jan/16/sarcococca-sweet-box [Accessed 12 February 2017]

Boxhill Community pages http://www.boxhillcommunity.com/page.php?10 [Accessed 12 February 2017]

Buxaceae. Wikipedia https://en.wikipedia.org/wiki/Buxaceae [Accessed 12 February 2017]

Chilterns AONB Box Woodland Project 2013-2015. http://www.chilternsaonb.org/about-chilterns/box-woodland/box-history.html [Accessed 12 February 2017]

Frydrysiak, F. Instrument maker.  http://filipfrydrysiak.com/about-wood/ [Accessed 1 March 2017]

Gentry, A.H. & Foster,R. 1981. A new Peruvian Styloceras (Buxaceae): discovery of a phytogeographical missing link. Ann. Missouri Bot. Gard. 68:122-124.

Köhler, E. (2009). Neotropical Buxaceae. In: Milliken, W., Klitgård, B. & Baracat, A. (2009 onwards), Neotropikey – Interactive key and information resources for flowering plants of the Neotropics. [ http://www.kew.org/science/tropamerica/neotropikey/families/Buxaceae.htm.]

Stevens, P. Angiosperm Phylogeny Group: Buxales, Buxaceae   http://www.mobot.org/mobot/research/apweb/orders/buxalesweb.htm [Accessed 12 February 2017]

Tree of Life Web Project. 2006. Buxaceae. Version 13 January 2006 (temporary). http://tolweb.org/Buxaceae/20712/2006.01.13 in The Tree of Life Web Project, http://tolweb.org/ [Accessed 5 March 2017]

Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 19th October 2016. delta-intkey.com [Accessed 12 February 2017]