An introduction of Ulmus elongata (长序榆简介)

Gao Jianguo

Ulmus elongata was first identified and classified as an Ulmaceae and Ulmus plant species by Chinese plant taxonomist Fu Liguo in Suichang County, Zhejiang Province, China (Fu, 1979).

长序榆是一榆科、榆属植物，1979年由中国植物分类学家傅立国在浙江遂昌发现 (Fu, 1979)。

 Its inflorescence, pedicel, and perianth characteristics, inflorescence position, and flowering season are similar to those of elm trees growing in North America and Mexico, and they are in fact classified as a single species, U. elongata (Sect. Chaetoptelea (Liemb.) Schneid.) (Fu, 1980).

其花序、花梗及花被性状，花序着生的部位以及开花的季节，与产于北美的墨西哥长序榆和翼枝长序榆等几个种相一致 (傅立国, 1980)，故归为一组，称长序榆组 (Sect. Chaetoptelea (Liemb.) Schneid.) (Fu, 1980)。

The discovery of U. elongata showed that Ulmus species extended from Asia, significantly prompting further research into North America and East Asia flora.

长序榆的发现佐证了榆属植物发源于亚洲，对研究北美和东亚的植物区系有重大意义。

 U. elongata is still sparse in China, and it inhabits highly fragmented habitats — for which it was thus declared a state-protected plant in 1999 (SFA and MOA, 1999).

根据我们最近几年的踏查，发现长序榆生境严重片段化，呈高度散生状态，数量稀少，在1999年被确立为国家二级重点保护植物 (SFA and MOA, 1999)。

The stem of U. elongata is straight and tall, grows rapidly, and has potential value as a source of medicinal agents and timber.

长序榆树干通直圆满，生长迅速，被认为具有潜在应用药用和材用价值的树种。

The cutting breed of U. elongata is of the root callus type (Lai, 2000; Tian et al., 1996), and the seedling basal segment is the best material for asexual reproduction (Zhang et al., 1993). The number of sprouts is positively correlated with the diameter of the mother tree (Tian et al., 1997); moreover, air temperature is the major environmental factor affecting 1-year seedling growth (Zhang et al., 1993; Lai, 2001a & 2001b).

在扦插育种方面有人认为长序榆属愈伤组织生根类型(赖文胜, 2000; 田野等, 1996)，实生苗基段是最好的无性繁殖材料(张纪卯等, 1993)，长序榆萌条数量与母桩地茎呈正相关(田野等, 1997)，气温是一年生长序榆幼苗生长的主要环境因子(张纪卯等, 1993; 赖文胜, 2001a & 2001b)。

Light is the most important environmental factor for the photosynthesis of one year and current year seedlings (Gao et al., 2011). Annual average temperature is vital for determining the foliar chemical compositions, which makes the elm trees from seven different regions into four genetic groups (Gao et al., 2012). Interestingly, mean annual temperature is also the main environmental factor affecting ¹³C fractionation in U. elongata leaves, which explained 36% variation of δ¹³C values (to be published).

光照是影响长序榆一年生和当年生幼苗光合作用最关键的环境因子(Gao et al., 2011)。年平均气温决定了叶片化合物成分的多少，从而使七个分布地的长序榆划分成四个基因类群(Gao et al., 2012)。年平均气温也是决定¹³C分馏的主要环境因子，单独解释δ¹³C变异的36% (待发表)。

We transplanted several saplings from Nanping, Fujian and Linan, Zhejiang in 2009, they did grow fast. The pictures below shown to you were photographed by Gao， including branches and small or mature leaves.

2009年我们从福建南平和浙江临安移栽了部分长序榆幼苗和幼树，它们确实生长迅速。下面的照片由高拍摄，照片主题是长序榆幼苗和幼树的枝叶、嫩芽和成熟叶片。

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Key references:

Fu, L.G. 1980. The research on Ulmus plants in China. J. Northeast Forest Univ. 3, 1-40.

Fu, L.G., Chen, J.R., Tang,Y.C. 1979. The Flora of Ulmaceae in China. J. Syst. Evol. 17, 45-47.

Gao, J.G., Wu, Y.H., Xu, G.D., et al. 2012. Phylogeography of Ulmus elongata based on Fourier transform-infrared spectroscopy (FTIR), thermal gravimetric and differential thermal analyses, Biochem. Syst. Ecol. doi:10.1016/j.bse.2011.10.018.

Gao, J.G., Xu, G.D., Li, W.Q., et al. 2011. Preliminary studies on photosynthetic characteristics of endangered plant Ulmus elongata seedlings. Ecol. Environ. Sci. 20: 66-71.

Lai, W.S. 2000. The Study on Cuttings propagation of Ulmus elongata. China Forest. Sci. Technol. 14: 32-33.

Lai, W.S. 2001a. Study on Annual Growth Dynamics of One-year-old Seedlings for Ulmus elongata. J. Nanjing Forest. Univ. (Nat. Sci. Ed.). 25: 57-60.

Lai W.S. 2001b. The Height Growth of Ulmus elongata Seedlings and Its Correlations with Climatic Factors. J. Fujian Coll. Forest. 21: 157-160.

State Forestry Administration and the Ministry of Agriculture, P. R. C. 1999. List of Wild Plants Under State Protection (First Batch). Decree No. 4. http://www.gov.cn/gongbao/content/2000/content_60072.htm

Tian, Y., Dong, T.M., Lai, W.S, et al. 1996. Study on the reproductive characteristics of Ulmus elongata. J. Hebei Forest. Coll. 11: 25-29.

Tian, Y., Zhu, Y.L., Kong, L.S., et al. 1997. Experiments on seedlings of Ulmus elongata in orchard. J. Fujian Forest. Sci. Technol. 24: 80-82.

Zhang, J.M., Chen, Q.N., Lai, W.S. 1993. Primary study on cuttings propagation of Ulmus elongata. J. Fujian Forest. Sci. Technol. 20:18-23.