Schima

New foliage of Schima. Photograph by Peter Clements

New foliage of Schima. Photograph by Peter Clements

On the way to Darjeeling…the roads…from March to May are found strewn over with the white flowers of Schima Wallichii.

K Biswas, Plants of Darjeeling and the Sikkim Himalayas, Volume I

Schima is an attractive genus of evergreen trees from subtropical and warm-temperate regions of Asia. A member of the tea family (Theaceae), schima is closely related to Gordonia, a genus found in Southeast Asia and the southeastern corner of the United States. Schima occurs at elevations of 660 to 8,250 feet (200 to 2,500 meters), from Nepal and India eastward to Taiwan. Most become quite tall—some reportedly exceeding 130 feet (forty meters). They have showy, fragrant white flowers, one and a half to two and a half inches (four to six centimeters) in diameter, with five petals and numerous yellow stamens. These appear on short pedicels in the terminal axils of the spring growth and are accompanied by a flush of delicate, shiny red new leaves. Once considered to comprise up to fifteen species, it is now thought to be only one variable species, according to a revision of the genus published in 1952 by Bloembergen, who placed them all under S. wallichii (DC) Korth.

I have seen and collected seeds from schima in the wild in four different areas. The first was a single tree in western Sichuan Province, China, on Erlang Shan at 5,990 feet (1,820 meters) elevation, found in October, 1991. A narrow tree, about twenty-three feet (seven meters) tall, it was growing among dense regenerating vegetation. The steep mountainsides had previously been logged and were now a “jungle” of competing trees and shrubs. The few seed capsules, found near the top of the tree, were brown, globular, about three-fifths inch (1.5 centimeters) across, and similar to those of camellias. Growing nearby were trees of Carpinus fangiana, Pterostyrax psilophylla, and Idesia polycarpa, along with a number of rhododendrons, hydrangeas, roses, clethras, and viburnums. I have been to Erlang Shan several times, finding it to be wet and almost always raining. The Erlang Shan typically receives over four feet (1.2 meters) of rain during the summer months, with occasional rain throughout the rest of the year.

The next time that I collected schima was in October, 1992, while returning from the town of Muli, west of Xichang in southwestern Sichuan Province at 7,700 feet (2,330 meters) elevation. Again, there was only a single narrow tree in an area of dense regenerating trees and shrubs. Like Erlang Shan, this area also receives heavy summer rainfall, although the annual total is less.

In Nepal, I again collected schima in October, 1993. Called chilaune by the locals, it is used in construction and for medicine. The leaves and roots are used for fevers and the bark is sometimes used for intestinal worms. The trees were growing at an elevation of 5,250 feet (1,590 meters), just west of Nargarkot. Here they were plentiful, dominating the north-facing mountainsides along with Pinus roxburghii, Castanopsis indica, and Alnus nepalensis. They had rounded crowns and were from twenty-three to thirty-three feet (seven to ten meters) tall.

My final collection of schima was in Taiwan in October, 2004. Here they were abundant and tall, with some reaching one hundred feet (thirty meters) in height. Ignoring Bloembergen’s revision, local botanists consider this one to be Schima superba Gardn. & Champ. They were growing on a steep northwest-facing mountainside with Acer serrulatum, Alnus formosana, Abies kawakamii, and Tsuga
chinensis
var. formosana at an elevation of 7,100 feet (2,150 meters) in Taroko National Park. Locally, the wood is used in construction; the bark serves as a fish poison.

Schima at Quarryhill Botanical Garden. Photograph by  Peter Clements

Schima at Quarryhill Botanical Garden. Photograph by Peter Clements

At Quarryhill Botanical Garden

Although schima’s bark is said to be a skin irritant, I suffered no harm from climbing any of these trees to gather the seed capsules. Of the four collections, only the first two have germinated for us at Quarryhill Botanical Garden. (It is too soon to know if the final collection will germinate, as it was only sown in December, 2004.) From the 1991 collection, we now have two vigorous trees, one over thirty feet (ten meters) tall and the other twenty-three feet (seven meters) tall; both are twenty feet (six meters) wide, after only twelve years in the ground. Three others that were planted around the same time have succumbed to oak root fungus (Armillaria mellea). All of these seedlings were planted within a few months of each other in 1992. The survivors are both in full sun on a gentle west-facing slope. We also have one young tree started from a cutting, planted in 2001; it is eight feet (2.5 meters) high. All three trees have developed as low-branching, single trunked trees and have dark green leaves, seven by two inches (eighteen by five centimeters), with serrate leaf margins. They begin flowering in September and have two large bracts enclosing the bud.

From the 1992 collection, we have two plants in the garden. The first was planted in the summer of 1994 and has grown more slowly than those from the previous collection, reaching a height of only twelve feet (3.5 meters) in ten years. The other, begun as a cutting of the first, was planted in 2001. They are both developing into rounded shrubs, almost as wide as they are tall, with considerably smaller flowers than the trees from the 1991 collection. Their bluish leaves are roughly half the size of those on the older plants, and they have entire margins. They start flowering in July and have much smaller bracts surrounding the bud. All of our trees, from both collections, have taken five years to flower in our garden.

A Challenging Nomenclature

Curious about the reasoning behind the lumping of all species of Schima under one name, I found several peculiar inconsistencies in the available literature. In leaf shape, our two collections of schima appear to match two of the line drawings in Krussmann’s Manual of Cultivated Broad-Leaved Trees & Shrubs. Krussmann ignores Bloembergen’s 1952 revision and states that there are fifteen species. He describes three of them: S. argentea Pritzel., S. khasiana Dyer, and S. wallichii (DC) Korth. The three accompanying line drawings, however, are of S. argentea, S. wallichii, and S. noronhae. Leaves on our 1992 collections are similar to the drawing of S. argentea, whereas those from the 1991 collection are similar to the drawing of S. noronhae. Krussmann’s line drawings are actually taken from the Iconographia Cormophytorum Sinicorum Tomas II. Despite a drawing labeled S. noronhae, the text implies that S. noronhae should be S. wallichii.

The descriptions of two species of Schima in Bean’s Trees & Shrubs Hardy In The British Isles seem to match our trees. Those from our 1991 collection appear to be what he calls S. khasiana; those from the 1992 collection appear to be what they call S. argentea. Bean does mention the revision, however, and goes on to state that S. khasiana should be known as S. wallichii subsp. wallichii var. khasiana and that S. argentea should be known as S. wallichii subsp. noronhae var. superba.

Flowers and foliage of Schima. Photograph by  Liam McNamara

Flowers and foliage of Schima. Photograph byLiam McNamara

Several of the horticultural references note that the flower buds are red or scarlet. All of our schima have creamy white buds.

Some references report flowering in April, May, and/or June. Frank Kingdon-Ward, in Plant Hunter in Manipur, mentions seeing schima “covered in June with large Camellia-like fragrant creamy white flowers with a large central brush of orange stamens.” Roy Lancaster in A Plantsman in Nepal, writes “the schima with its attractive white fragrant camellia-like flowers in April to June make a magnificent tree . . . in the eastern Himalaya.” In the Trees and Shrubs of Nepal and the Himalayas, one reads “The flowers, which appear in May . . .” Lastly, according to Flowers of the Himalaya, Schima wallichii flowers in May-June.

Ours, however, flower in late summer and into the fall. The Manual of Cultivated Broad-Leaved Trees & Shrubs says that Schima argentea blooms in August, S. khasiana blooms in September-October, and S. wallichii blooms in the late summer. The Hillier Manual of Trees & Shrubs, despite mentioning Bloembergen’s revision, describes four species, with S. argentea blooming in late summer, S. khasiana blooming in September and October, S. noronhae blooming in late summer and autumn, and S. wallichii blooming in late summer.

In the paragraph above, all of the descriptions were of plants observed in the wild; those referred to as blooming in the late summer and autumn were all cultivated trees. Perhaps this variation in flowering season is an anomaly of cultivation in Western Europe and North America. I did, however, see a few lingering flowers on naturally occurring plants in Taiwan last October.

Cultivation

In discussing the cultivation of schima, The New Royal Horticultural Society Dictionary of Gardening mentions that they should be protected from frost when young and that, if grown under glass, the temperature should not drop below 37–41° F (3–5° C). Ours were planted out while quite young (one to two years from seed) and have experienced numerous frosts each winter with temperatures as low as 18° F (–8° C). Both were less than twelve inches (thirty centimeters) high in four-inch pots when planted in the ground; none have suffered from our frequent frosts.

Clearly, our experience has shown that Schima have promise as ornamental trees in California and perhaps in milder areas along the West Coast. In addition to showing no frost damage in Sonoma County (Sunset zone 14/15), they have withstood our intense summer sun with no hint of sunburn. To date, there are no signs of insect damage either. Unlike some introduced exotics, they have not reseeded in our garden, nor have they suckered. They are also resistant to fire. Though not heavy bloomers, they are in flower at a time when little else is. Their lush evergreen leaves have a cooling effect in summer and contrast nicely with winter’s starkness. Other than their occasional susceptibility to oak root fungus, which I believe can be ameliorated through proper culture, they seem to be ideal ornamental trees. The fragrant white flowers of this little known tree could easily compliment many gardens.


For Further Reading

Bean, WJ. Trees & Shrubs Hardy in the British Isles, Volume IV. London: John Murray Ltd, 1989.

Biswas, K. Plants of Darjeeling and the Sikkim Himalayas, Volume I. Alipore, West Bengal, India: West Bengal Government Press, 1966.

Hillier, Harold. The Hillier Manual of Trees & Shrubs. Devon, England: David & Charles, 1992.

Kanehira, R. Formosan Trees. Tokyo, Japan: Inoue Book Company, 1973.

Kingdon-Ward, Frank. Plant Hunter in Manipur. London: Jonathan Cape, 1952.

Krussmann, G. Manual of Cultivated Broad-leaved Trees & Shrubs, Volume III. Portland, Oregon: Timber Press, 1986.

Lancaster, Roy. A Plantsman in Nepal. Woodbridge, Suffolk, England: Antique Collectors’ Club Ltd, 1995.

Polunin, O. and A Stainton. Flowers of the Himalaya. New Delhi, India: Oxford University Press, 1988.

Storrs, A. and J Storrs. Trees and Shrubs of Nepal and the Himalayas. Kathmandu, Nepal: Pilgrims Book House, 1990.