1. Glyptostrobus pensilis (Staunton ex D. Don) K. Koch, Dendrologie. 2(2): 191. 1873.
水松 shui song
Thuja pensilis Staunton ex D. Don in Lambert, Descr. Pinus, ed. 2, 2: 115. 1828; Glyptostrobus aquaticus (Antoine) R. Parker; G. heterophyllus (Brongniart) Endlicher; G. sinensis A. Henry ex Loder; Sabina aquatica Antoine; Taxodium japonicum (Thunberg ex Linnaeus f.) Brongniart var. heterophyllum Brongniart; T. sinense J. Forbes.
Trees to 15(-25) m tall; trunk to 1.2 m d.b.h., basal part (ca. 0.7 m) buttressed; bark brown or grayish white with brown tinge, cracking into long, irregular strips; main branches spreading horizontally; lateral branchlets in 2 rows, those of older branches often very dense and broomlike. Scale leaves on mature branchlets appressed, 1.5-3 × 0.4-0.6 mm, with scattered, white, stomatal spots, adaxial surface convex, base decurrent, apex incurved, slightly hooked. Leaves of 1st year branchlets erect-spreading at 40-45° to axis, 1.5-2 mm apart, forming a narrowly oblong-lanceolate branchlet outline, subulate, slightly falcately recurved distally, 2-7 × 0.4-0.6 mm, with stomatal lines along all surfaces and on branchlet axis, trailing edge with narrow, membranous wing decurrent onto branchlet axis. Seed cones obovoid, 1.4-2.5 × 0.9-1.5 cm; bracts ± connate with cone scales except for triangular apex located in middle or distal middle part of cone scale; cone scales flattened, median scales obovate, 1-1.3 cm × 3-5.5 mm, base cuneate, apical margin with 6-10 triangular, outwardly curved teeth adaxially. Seeds brown, elliptic, slightly flattened, 5-7 × 3-4 mm, with a basal wing 4-7 mm. Pollination Jan-Mar, seed maturity Sep-Oct(-Nov), persisting until following spring.
River deltas, etc., on flooded or waterlogged soil in full sun; near sea level. Fujian, S Guangdong, S Guangxi, Hainan, E Jiangxi, E Sichuan, SE Yunnan (Pingbian Miaozu Zizhixian), Zhejiang [N Vietnam (extinct in the wild)].
May no longer exist in the wild anywhere in China; rare in all provinces except Guangdong. Most frequent along the Zhu Jiang delta, in Guangdong, and along the lower reaches of the Min Jiang in Fujian, but possibly not native in the latter province. Somewhat similar in vegetative features to the introduced Taxodium distichum var. imbricatum, which is planted in similar habitats within the range of Glyptostrobus pensilis. The former differs in its flat leaves (of young branchlets), which lack a narrow wing along their trailing edges, and in its subulate, spreading leaves (of 1st year branchlets on older trees), which are softer, with incurved (not recurved) apices.
Wind-felled trees are used in constructing buildings, bridges and furniture. The roots have high buoyancy and are used to make life buoys, bottle corks, etc. Tannins extracted from the bark and the cone scales are used in tanning, dyeing, and fishing nets. Often planted in wet places for erosion control, as a windbreak, and because it is believed to bring good luck; consequently the tree is not normally deliberately felled by villagers.