705. CARPINUS FANGIANA Betulaceae. Roy Lancaster and Martyn Rix

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1 705. CARPINUS FANGIANA Betulaceae Roy Lancaster and Martyn Rix Summary. Carpinus fangiana Hu, from wet mountains of western China, is illustrated and described. Its habitat and associated species are discussed. The genus Carpinus consists of around forty species with several subspecies and varieties; thirty-one species are found in China (Li & Skvortsov, 1999). The widespread Carpinus betulus L., which occurs throughout Europe, and most other specieshave loosely overlapping, lobed or deeply toothed bracts on the female inflorescence, whereas four far-easternspecies have closely imbricated, unlobed bracts forming a hop-like inflorescence, similar to that found in the related genus Ostrya Scop. In Ostrya the fruit is enclosed in the bladder-like bract, whereas in Carpinus the bract is wrapped around the fruit. These four species of Carpinus are separated in section Distegocarpus Sargent, based on Distegocarpus carpinus Sieb.&Zucc.,asynonymofC. japonica Blume (Sargent, 1916). The species illustrated here, Carpinus fangiana Hu, is easily distinguished from all other species by its very large leaves with pairs of veins and very long female inflorescence. In his original description, Hu (1929) compared it with the widespread Carpinus cordata Blume, which may have leaves to 15 cm long, with pairs of veins and a female inflorescence to 12 cm long. Carpinus rankanensis Hayata, from Taiwan, has leaves with pairs of veins and long-acuminate teeth, and can also have an inflorescence cm long (Li & Skvortsov, 1999). Fang Wen Pei ( ) after whom this species was named, was born in Sichuan and based for many years in the department of Biology of Sichuan University in Chengdu. He took his doctorate at Edinburgh in 1937, and then collected extensively in western China, studying in particular the trees of Mount Omei and neighbouring areas, and the genera Acer and Rhododendron. He collected over specimens and discovered over 100 new species (Lancaster, 2008). His illustrations of the woody plants of Mount Omei, Icones Plantarum Omeiensium, with detailed woodcuts printed on ricepaper, were published between 1942 and 1945, in very difficult conditions. Curtis s Botanical Magazine 2011 vol. 28 (2): pp The Board of Trustees of the Royal Botanic Gardens, Kew

2 His other publications include a revision of Chinese Acer in 1966 and an account of Chinese Rhododendron, which formed the basis of Rhododendrons of China, published by the American Rhododendron Society and Rhododendron Species Foundation (1980). He was editor of, and a major contributor to, Flora Sichuanica vol. 1 (Fang, 1981). Carpinus fangiana is found in dense deciduous or mixed forest in areas with much summer cloud and high rainfall. The original collection was from Nanchuan Xian, in southeastern Sichuan, near Chongqing, probably on the slopes of Jinfo Shan. It is also recorded in southwest Sichuan and northeast Yunnan as well as in Guizhou and Guangxi (Li & Skvortsov, 1999). The first introduction to cultivation in the west was a collection of seed by Mikinori Ogisu in south Sichuan in October 1991 (Ogisu 91103). The locality was at 1750 m, at Shanlengyong, , in Leibo Xian, around 270 km south of Chengdu. Seedlings were distributed, and the tree from which the specimen illustrated here was taken, was grown by Roy Lancaster in Hampshire. In 1993 Mikinori Ogisu took our mutual friend John Joe Costin and myself (RL) to this location which we reached on June 3. It was a long day and an early start and no sooner were we on the road than we began to make frequent stops to examine the roadside vegetation which was predictably rich. At around 1900 m we made a prolonged stop to explore the surrounding forestwhich was in pristine condition and comprised a stunning mix of broad-leaved deciduous and evergreen trees rising above a dense understorey of bamboo Chimonobambusa tumidissinoda Ohrnb., with its characteristic swollen nodes. Among the trees we identified Rehderodendron macrocarpum Hu, Fagus longipetiolata Seemen, Davidia involucrata Franch., the evergreen Castanopsis platyacantha Rehd. & Wils., plus several maples including Acer oliverianum Pax and A. laxiflorum Pax. Other trees in the forest were Acer cappadocicum var. sinicum, Cornus controversa, Prunus buergeriana Miq., Cercidiphyllum japonicum Sieb. & Zucc. and Tetracentron sinense Oliv. Our joy at seeing these trees, however, was increased by the presence of Carpinus fangiana, superb specimens with strong stems and semi-weeping, wide-spreading crowns of m or more, clothed with their characteristic large, impressively-veined leaves and strung with their equally impressive green fruiting catkins, like lambs tails. Many trees were multi-stemmed, some clothed with the 104 The Board of Trustees of the Royal Botanic Gardens, Kew 2011.

3 Plate 705 Carpinus fangiana christabel king

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5 high-climbing Hedera nepalensis var. sinensis. They occurred as scattered individuals in the forest which clothed the steep slopes. A second collection in October 1991, by John Simmons, Charles Erskine, Charles Howick and William McNamara,SICH 842, planted in 1994, is growing well and now flowering in the arboretum at Kew. It was collected on the pass over Erlang Shan, west of Ya-an, where it occurs scattered through a very species-rich woodland, on precipitous north and east-facing slopes, along the now abandoned road over the pass (see Fig.1). Schima sinensis (Hemsl. & E.H. Wilson) Airy-Shaw was growing nearby, and collected under SICH 843 (McNamara, 2009). The old road, which was the main route for porters carrying bricks of tea from Ya-an into Tibet, zigzagged up the precipitous east side of the pass, cut out of cliffs and often passing underneath waterfalls; fatal accidents were frequent. The motor road was built by the People s Liberation Army and opened in The vegetation changes from subtropical near Ya-an to grassland with scattered rhododendrons on the summit at around 3000 m. The west side is much drier and descends less precipitously to Luding, site of a famous chain bridge across the Dadu He. In 1996 a tunnel was opened beneath Erlang Fig. 1. The abandoned road over the Erlang Shan, west of Ya-an; habitat of a wide range of woody and herbaceous plants, including Carpinus fangiana, which have seeded onto the margins of the old roadway. Photograph: Martyn Rix. The Board of Trustees of the Royal Botanic Gardens, Kew

6 Shan, at around 1600 m, and since then the old road has been allowed to become overgrown and blocked by fallen trees and mud slides. Cultivation. This species seems to thrive in shelter, the ideal spot being a clearing in moist woodland. In a warm and sheltered garden in Hampshire (RL s) this species has grown very well and formed a dense shrub around 5 m tall, which fruits freely. In cooler, wetter North Devon (MR s), three seedlings of the original collection grew very fast at first in a clearing in old woodland, but two died suddenly while in full growth, whereas a slower-growing survivor has persisted, surrounded by other trees. Where two different clones are grown together, viable seed should be formed. Until now most propagation has been by grafting, but grafted plants seem to grow more slowly. Carpinus fangiana Hu, J. Arnold Arbor. 10:154 (1929). Type: China, Sichuan: Nanchuan Xian, in thickets, m, June 1, W.P. Fang (Holotype HUH, isotype A). Description. Tree to 20 m, or multi-stemmed shrub, with rough dark brown or grey bark. Twigs smooth, c. 2 mm in diam., brown with conspicuous lenticels; dormant buds large, spindle-shaped, to mm long, 4 mm wide, green with brown-margined scales. Leaves alternate, ovate-lanceolate, ellipticoblong or oblong-lanceolate, apex acuminate, base obliquely cordate, with pairs of parallel veins, 6 25 cm long, cm wide, finely serratedentate, rather thin in texture, glabrous above, with appressed hairs on the veins and midrib beneath. Male catkin 4 10 cm long, bracts laciniate-dentate, with 20 or more, forked stamens; anthers with a tuft of hairs at the apex. Female inflorescence with styles emerging from swollen bud. Fruiting inflorescence to cm (to 50 cm long fide FOC), 2 4 cm in diam.; bracts papery, broadly ovate, with shallow teeth near apex and on inner margin, not lobed, overlapping to form a long cylinder. Nutlet oblong, ca 3.5 cm long, glabrous. Distribution. N Guangxi, Guizhou, Sichuan, E. Yunnan. Habitat. Sheltered valleys and shady mountain slopes, m. Flowering Time. May to June; fruiting July to September. Carpinus fangiana. A, Margin of leaf underside, 3; B, Male catkin: bract and stamens abaxial view, 6; C, malecatkin, bract andstamensadaxial view, 6; D, stamen, 12; E, bud with female catkin coming into flower in March: bud scales opened out, 2; F, female catkin in March: young involucre and bract from proximal part of catkin, abaxial view 10; G, female catkin in March: involucres and bract from distal part of catkin with styles withering, abaxial view, 10; H, female catkin in May: immature involucre, adaxial view, 2; J, female catkin in May: immature involucre with withered bract, abaxial view, 2; K, female catkin in September: involucre with seeds still attached to axis, 1 1/ 2; L, ripe seed within floral bract, adaxial view, 2; M, floral bract, abaxial view, 2; N, seed, 6. The bar at lower right is 10 mm when printed. Drawn by Christabel King, the flowers from specimens of Sich 842 at Kew, and the fruiting material from Ogisu The Board of Trustees of the Royal Botanic Gardens, Kew 2011.

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8 REFERENCES American Rhododendron Society and Rhododendron Species Foundation (1980). Rhododendrons of China. Binford & Mort, Portland. Fang, W.-P. (ed.) (1981). Flora Sichuanica Tomus 1. Academia Sinica, Chengdu. Hu, H.H. (1929). Two new species of Carpinus from Szechuan. Journal of the Arnold Arboretum 10: 154. Lancaster, R. (2008). Plantsman s Paradise. Travels in China. Garden Art Press, Woodbridge, Suffolk. Li, P.-C. & Skvortsov, A.K. (1999). Betulaceae. In: Flora of China. Vol. 4., St Louis, Missouri and Beijing, pp McNamara, W.A. (2009) Schima sinensis. Curtis s Botanical Magazine 26(3): Rehder, A. & Wilson, E.H. in Sargent, C.S. ( ed.) (1916). Plantae Wilsonianae. Vol. 2. Publications of the Arnold Arboretum No.2: Cambridge University Press, Cambridge, Mass. 110 The Board of Trustees of the Royal Botanic Gardens, Kew 2011.