Unusual Trees around Manchester
Hello! My name is Josh and I am new to the herbarium. I am a member of the faculty of life sciences at the University of Manchester, and for the work placement part of my degree it is my pleasure to spend a year working in the herbarium with Rachel and Lindsey . This is only my first week but we’ve already been busy collecting lots of tree samples from the array of trees we have on campus. Henry McGhie, Dr Webster and I started out by recording the geographic location of each tree we sampled, measured the girth of each tree’s main trunk and took small clippings of the leaves (and fruits in some cases!) Samples included the tulip tree, genus Liriodendron. The British crab apple tree, family Rosaceae and the Willow tree Salix.
Araucaria heterophylla, Norfolk Island Pine 165/24
Meaning: The genus is named for the Araucaria Indians of Patagonia, and heterophylla = different-leaved, referring to the conspicuous difference between young and mature plants. Sometimes also called “star pine” because of its symmetrical shape as a sapling. Synonym: A. excelsa. There are 19 species in the genus.
No more a pine than the Chile Pine (Monkey-Puzzle Tree), these survivors of a very old coniferous family are scattered around the Pacific and of course, Chile. From an origin in the Triassic, the family expanded and diversified in both hemispheres in the Jurassic and Early Cretaceous and remained a significant component of Gondwanan vegetation until the latter part of the Cenozoic. Norfolk Island is located between Australia, New Zealand and New Caledonia, and the genus is especially concentrated about 700 km north of Norfolk Island, where 13 closely related species are found. In their native habitat A. heterophylla can grow to a height of up to 65m.
According to two supposedly authoritative sources, the only known outdoor specimen in the British Isles is in the Scillies, but I think this may be out of date. In recent years, they have had some popularity as an indoor potted Christmas tree, although they need some care to flourish. Outdoors, although they’re known to be quite happy in salt and wind, they’re said not to survive in areas of prolonged cold. Some people may have a strong allergic reaction if they touch the leaves. They are, however, widely planted in Australia, New Zealand, southern Florida, coastal California, south Texas, Hawaii, coastal Chile, South Africa, and some cities of Brazil.
There’s a considerable bit of history attached to Norfolk Island and its ‘pines’, and other plants, too, particularly New Zealand flax. It was made a penal colony in the 1780s, mainly for Australian convicts who were too mutinous even for Australia, and this practice continued until 1847. Meanwhile, in 1789, the Bounty mutineers had been marooned on Pitcairn Island. They intermarried with Tahitians, and by 1856, 194 of their descendants, who had become too numerous for Pitcairn, were allowed to resettle on Norfolk. The story of how the settlers had planted two rows of the pines to create a magnificent avenue, and how, now a majestic 80 feet tall and six feet in diameter, they came to be cut down in the course of World War II in the Pacific, is told in James A. Michener’s Tales of the South Pacific, Chapter 3, “Mutiny”. We also have Michener’s book to thank for the musical. The island of Bali-ha’i in the stage story and film is said by no less an authority than Stephen Jay Gould to be based on the island of Moorea, and some of Moorea’s natural history is also the subject of an essay in Gould’s Eight Little Piggies.
Araucaria araucana, Monkey-Puzzle Tree 165/24
Meaning: As above, plus species named for the Araucano Indians of Chile.
The tree was first found in Chile in the 1780s by the botanical explorer Molina. Before 1850, it was known in England as “Joseph Banks’s Pine” or “Chile Pine”. In about 1850, when it began to be cultivated in England, the species was still very rare in gardens and not widely known. The proud owner of a young specimen at Pencarrow Gardens near Bodmin, in Cornwall, was showing it to a group of friends. One remarked that “It would puzzle a monkey to climb that”, and the name “Monkey-puzzle” stuck as a popular term.
A. araucana in Whalley Range, Manchester
In the mountains of Chile
A big thank you to Botany volunteer Dan King for the idea, words and images of ‘Unusual Trees Around Manchester’.
Cordyline australis, Cabbage Palm 178/43
Meaning: Club-like (roots), southern
A native of New Zealand, where it’s usually called Ti rakau or Ti kouka in the Maori language. It can grow up to 15 m, starting on a single stem, but later branching after flowering into several more, each branch producing a flowering stem. It is a monocoyledon, and each stem grows from a single central bud.
The tree has a high carbohydrate content and was long used as a food source by the Maori. The sword-shaped leaves, the trunk and the root material were also valuable sources of fibre for making into clothing and footwear. The juice of the tree has antibacterial properties, and the tree is said to be a potential source of ethanol.
It is widely planted as an ornamental tree, particularly because it tolerates cold weather well; this has earned it other names like “Torbay Palm” and “Manx Palm”. The subspecies atropupurea and other colour variants are much in demand for gardens. Incidentally, and just to confuse us, the name “Cabbage Palm” is also used to refer to some other species, such as the palmettos.
The local trees of this species have taken a bit of a beating in this year’s snows, unfortunately. This photo, however, shows the tree in New Zealand:
Curator of Mineralogy – Dr. David Green’s palm, grown from seed, winter 2009-10, Manchester
Unfortunately, since 1987, the Cordylines in New Zealand have been affected by a pathogen, Phytoplasma australiense, and suffer from a disease called “Sudden Decline”. It usually causes almost total defoliation in between 2 and 12 months.
C. atropupurea after the 2009-2010 snows in Manchester…
…and another, C. australis.
Taxodium distichum, Swamp or Bald Cypress 165/9
Meaning: Yew-like, two ranks (referring to leaf arrangement)
Do you think all conifers are evergreen? Think again. This one’s deciduous, dropping its leaves in late November or December and being fully back in leaf around June. There’s a handsome stand of half-a-dozen mature examples in the arboretum at Jodrell Bank. This North American native was introduced in 1640; one of the largest British examples is at Syon House, Brentford, Middlesex, and measured 90’ x 14’-9” in 1968. It was planted in 1750. Our Manchester example here is just off Old Birley Street in Hulme, on vacant land opposite ASDA. It’s clearly kept in gaol for its own good, but a rogue sycamore maple has found its way into the same cell. The winter photo was taken in February 2010, the summer one in May.
Catalpa bignonioides, Indian Bean Tree, 120/023
I spotted this fairly young catalpa in Albany Road, Chorlton, Manchester. The tree is native to the eastern half of United States, and actually has nothing to do with India. Its official spelling is also a misnomer. The botanist who first described it, Giovanni Scopoli, presided over a mistranscription of the spelling of the Native American Indian tribe, the Catawba, whose totem the tree was, and after whom he wanted to name it. A larger specimen than the one in the photo above can be seen near the Old Broadway entrance to Fog Lane Park in Didsbury. Four young catalpas have been planted in front of recently refurbished flats at the corner of Whitelow Road and High Lane in Chorlton.
The Indian bean tree was introduced to Britain in 1726 and has been planted widely ever since for its decorative and shade-giving appeal. The oldest known Catalpa bignonioides in Britain is in the Minster graveyard of St. Mary the Virgin, Reading, Berkshire. The twisted trunk is one of the major attractions of this 150-year-old tree, although the deteriorating health of this specimen led to its requiring extensive surgery in 2007. The largest living catalpa is in the grounds of the Michigan State Capitol in Lansing and was planted in the year of the capitol’s dedication, 1879.
The tree’s large, attractive heart-shaped leaves do not emerge until late June and continue to do so right through until September, when some are inevitably killed off by early frost. The leaves then fall without gaining any autumn colour. The tree usually comes into blossom in the middle of July with white flowers that have yellow and purple flecks. The flowers are produced in large clusters and can be so numerous as to obscure the leaves of the tree altogether. The catalpa is a genus of flowering plants in the Bignoniaceae, the trumpet vine family, native to North America, the Caribbean, and East Asia. They’re mostly deciduous trees that typically grow 12-18 meters (39-59 ft) tall and 6-12 meters (20-39 ft) wide. A 10-year-old sapling will stand about 6 meters (20 ft) tall.
The catalpa’s bean-like pods are very slim and almost perfectly cylindrical and can grow up to 16 inches in length. These pods contain winged seeds and remain on the tree throughout the winter before splitting and releasing the seeds.
Sheets from the Grindon Herbarium:
Pterocarya fraxinifolia, Caucasian Wingnut Tree, 156/003
The Caucasian Wingnut tree in Beech Road Park, Chorlton, Manchester, is a particularly fine example of this specimen tree, which was sometimes planted in our Victorian and Edwardian parks. It is occasionally characteristic of the trunk of this species to divide into two main branches not far off the ground. It belongs to the walnut family (Juglandaceae) and is native to the eastern Caucasus, northern Iran and eastern Turkey. In its native habitat it can reach nearly 100 feet in height, but in northern climates it reaches about 80 feet, with a branch spread of 70 feet. Because of its nearly cubic proportions and because it is relatively fast-growing, it is prized as a shade tree. In a good year, the tree in late summer or early autumn is a delightful and strikingly decorative sight, festooned with its long, pale-green strings of seeds.
BBC Plant finder: “This superb, very large tree is rarely seen in the UK due to its enormous size: there are few gardens big enough to accommodate one. However, there are two excellent specimens in Cambridge and Sheffield Botanic Gardens that show how striking this plant can be. The tree has green leaves that can grow to over 60cm (2ft) long and that turn butter-yellow in autumn. In the summer, it produces eyecatching chains of green catkins that can grow up to 60cm (2ft) long. In its native Iran, it is often found growing by rivers, so its favoured position is in a moist, almost boggy soil where it can also get plenty of light.”
Sheets from the Grindon Herbarium
Pinus wallichiana (Pinaceae), Bhutan Pine 165/026
This one’s named after Dr. Nathaniel Wallich (1786-1854), who was born in Copenhagen but who spent much of his life exploring the botany of northern India and nearby areas. Wallich was among the most prominent botanists of his times. He introduced the seeds of this pine into England in 1827. The tree is native to the Himalaya, Karakoram and Hindu Kush mountains, from eastern Afghanistan east across northern Pakistan and India to Yunnan in southwest China. It grows in mountain valleys at altitudes of 1800-4300m (but rarely as low as 1200m), and reaches from 30-50m in height. It likes a temperate climate with dry winters and wet summers.
Our three photographs of living trees are of specimens in Sackville Gardens in the city centre and one in a churchyard in Chorlton, Manchester.
Specimen sheet from the Grindon Herbarium
Pinus aristata (Pinaceae), Bristlecone (Rocky Mountain) Pine 165/026
Aristata means bristle-tip, referring to the cone segments. The genus contains three species, including the Great Basin Bristlecone Pine, Pinus longaeva, which is thought to be the oldest living tree in North America. A ring count from a core sample gives an age of 4,700 years. The third species is Pinus balfouriana, or Foxtail Pine. All three are rare, and grow in the mountains of California, Nevada, Arizona, Utah and other western states. It was introduced here in 1863; the oldest known dated British tree is at Kew. It was planted in 1908 and in 1972 was 20’ x 1’-7”. Our three photographs are of a specimen aristata in Wythenshawe Park, Manchester.
“It differs most conspicuously from the two other bristlecone pine species in that the needles usually have only one, (only rarely two) resin canals, and these are commonly interrupted and broken, leading to highly characteristic small white resin flecks appearing on the needles. This feature, which looks a bit like dandruff on the needles, is diagnostic of Pinus aristata; no other pine shows it.” –Wikipedia
Unfortunately, my digital camera can’t cope very well with chiaroscuro contrasts, but I can assure you the white flecks are copiously present on the Wythenshawe Park tree’s needles.
Grindon Herbarium sheet with history of discovery of P. aristata
Unusual Trees to Look Out for (1)
Sciadopitys verticillata (Sciadopityaceae), Umbrella Pine 165/025
Sciadopitys is from two Greek roots, meaning (YES!) ‘umbrella’ and ‘pine’. Verticillata means ‘whorled’. A native tree of Japan, there called Koyamaki, it is said to be rare now.
It was introduced by John Gould Veitch into Britain in 1860. As you might guess from its appearance, it’s not a pine at all. It’s the sole member of the family Sciadopityaceae, and is a living fossil, having been present in the fossil record for 230 million years – the first known examples appearing in the Triassic period. At one time it was more widespread; fossils have been found in northern Europe. Research using infrared microspectroscopy has revealed that some of its close family members among the Sciadopityaceae are the source of Baltic amber. (It used to be thought that the amber was from members of the Araucariaceae and Pinaceae families.)
It has no close relatives, although it was formerly classified as a member of the family Taxodiaceae. (Demonstrating these matters of classification to be even more fluid, recent research has shown the Taxodiaceae to be part of the Cupressaceae family, which includes the cypresses, redwoods, cryptomerias, cedars and others. Even the usually authoritative International Plant Names Index still shows the tree as being in the Taxodiaceae.)
Our first two photographs are of a specimen tree in Wythenshawe Park, Manchester. I’ve also spotted a young tree, not much over a meter high, in the botanical woodlands at Portmeirion.
Portmeirion woodlands, 2009
Mature cone, New York Botanical Garden
Sheet from our Grindon Herbarium with illustrations from Louis van Houtte’s Flore des serres et des jardins de l’Europe and articles from The Gardener’s Chronicle and elsewhere.