从紫檀应用的层面看，紫檀木中包含的不止是一个树种，比较靠谱的证据可证1：药用的紫檀木(紫檀香)中即包括了印度紫檀和檀香紫檀两个树种，之前如此，现在仍如此。
至于器用的紫檀木中包括多少个树种，各种观点多有争论并未统一起来，它们已成为紫檀应用史研究的一部分。
到了公元2000年8月1日，《红木》GB/T18107-2000开始实施以后，檀香紫檀在该标准的"紫檀木类"中确立了独尊的地位2。标准的附录中只列了一个树种，这就是豆科紫檀属下的檀香紫檀Pterocarpus santalinus L.f.。
本文的主旨即对紫檀木的来源--檀香紫檀树的地理分布及生长概况，为喜欢紫檀的朋友们做一番尽可能详尽的介绍。
檀香紫檀Pterocarpus santalinus L.f.通常被称作紫檀，国内也称为小叶紫檀。是分布在印度东高止山脉南段的特有树种。为安得拉邦热带干旱落叶林中的一种典型豆科植物，主要分布在古德伯地区北纬13度30分到15度、东经78度45分到79度39分之间的地区。总的分布区域约5160平方公里，大致散布在奇多尔、古德伯、内洛尔等区内的Seshachalam山区零散森林中(海拔150~900米)，泰米尔纳德邦和卡纳塔克邦也有少量分布。
▲檀香紫檀产地分布示意2
图片来源：互联网
檀香紫檀自然栖息地的最低气温11℃、最高气温46℃，降水量约为100~1000mm，一年中大部分是非常干旱的气候。
檀香紫檀天然生长于干旱多岩石的丘陵山地，土质普遍浅薄、贫瘠、多石、排水良好。绝大多数(约80%左右)的树木生长在石英岩出露的地区，土壤大多为页岩、石英岩、砂岩发育而成，海拔高度约为 150~900 m。
檀香紫檀喜光、怕涝，重要的伴生植物主要有囊状紫檀、锡兰缎木、亚尼安苏木、宽叶榆绿木和阔荚合欢。檀香紫檀的生长情况3~6
1.树
檀香紫檀是一种中小型落叶树木，长成的大树具有密集的圆形树冠，高度约10~15m，周长约90~160cm。热带林业研究所的一项研究报告称：“檀香紫檀在印度Andhra邦，生长最好的人工林18年生时，年胸径生长量约1.0cm。而天然林，年胸径生长量为0.4～0.6cm”。▲檀香紫檀小树苗
图片来源：互联网
▲盆栽的檀香紫檀
图片来源:互联网
2.1 叶
树叶主为大头三出的羽状复叶，即叶轴上长有三片小叶；稀有5片。形状为卵形或近似椭圆，长约9~15cm，先端微凹，基部圆，网脉明显，革质。1至3月脱落，夏季花开树叶也随之长起来。▲檀香紫檀的树叶1
资料来源:互联网
▲檀香紫檀的叶子2
图片来源:互联网及@紫金紫檀拍摄
▲檀香紫檀的叶子3
图片来源:@紫金紫檀拍摄
2.2 花
一般年龄达到15年以上时才开花结果，每年的4~5月时会开出总状花序的黄色花朵，授粉形式以交叉授粉为主辅以少量的自株授粉。▲檀香紫檀的花
图片来源:互联网
2.3 果
果圆形，周围具翅，径3~5cm，开花11个月之后结果，成熟的翅果为红褐色，内有一至两粒种子。檀香紫檀翅果较耐贮藏，贮藏时以不剪除果翅为宜，保持果荚密闭从而减弱其透水和透气性，其种子活力可保持1 年以上。▲不同阶段的翅果
图片来源:互联网
小枝被灰色柔毛，成熟后的树树皮深褐色，并深深裂开，呈不规则的长方形。如果切开树皮，可见很多(色素所致的)粉红色条纹，很快变为深红色，并渗出红色树胶。檀香紫檀的木质部具直纹理和波状纹理2种类型，(从分类的层面讲，局部卷曲者不属于波状纹理)，具波状纹理的紫檀木价格是直纹理的数倍甚至更高。但其中波纹的紫檀数量极少，只有约1%的占比，无论天然林还是人工林皆如此。
研究者发现，同一地域中直纹紫檀和波纹紫檀均有生长，这说明了基因作用大于环境作用。
▲檀香紫檀 (直纹理)
图片来源:左图THE WOOD DATABASE,右图自拍5.2 波状纹理
▲檀香紫檀 (波状纹理)
图片来源:左图互联网,右图@紫金紫檀
天然林的覆盖范围越来越小已是不争的事实。印度有关林业部门提供的资料表明：“至本世纪初，檀香紫檀的天然林分布的范围进一步减少，主要集中于安得拉邦奇图尔林区”。天然林的更新主要依靠树桩发芽及人工嫁接，成活率较低且树桩易感染病菌。整体来说前景并不乐观。依靠种子进行人工繁育种植紫檀在印度有较长的历史，最远可以追溯到18XX年，但规模不大数量很少。真正有规模的人工种植只有几十年的时间。印度政府为了扩大种植面积，鼓励和扶持林农建立紫檀农场以增加产量。东南亚等许多国家、中国及中国台湾均有引种了檀香紫檀树。“孟加拉、斯里兰卡、缅甸、泰国、柬埔寨,老挝、越南、马来西亚、印度尼西亚均有紫檀人工种植，但其规模并未达到商业采伐的要求。
中国的云南的西双版纳、广西南宁、海南的儋州及尖峰岭、广州华南植物园等地有极少量的紫檀人工种植，主要用于科研。台湾地区也有紫檀人工林，数量也不大”。
▲檀香紫檀引种地人工林(海南儋州植物园)
图片来源:《紫檀》插图的翻拍
紫檀农场简介
注："紫檀农场简介"部分的资料全部采用了
@wml_rail 发于"紫檀玩家俱乐部"中的吧文。某紫檀农场的网址：
http://svsagrofarms.com/index.html
(网站已不能正常登陆，原因不明)
About SVS Agro Farms
Svs Agro Farms Developers is well established with qualified andexperienced Professionals, agriculture experts, biologists, marketing and otherskilled consultants SVS Agro Farms Developers has interest in developingagriculture lands. The company is based in Hyderabad,Andhra Pradesh,India. Interest in red sandalwood cultivation under the leadership of qualified experts.
Anticipating the ever-increasing gap betweendemand and supply of Red sandalwood, SVS Agro Farms Developers has taken up thecultivation of red sandalwood plantation. SVS Agro Farms Developers’ initiativeto undertake its own red sandalwood plantation is reflective of its long-termvision to be fully self-reliant and further consolidate its leadership in thered sandalwood business. It is a shining example of consolidation throughbackward integration.Red sandalwood being the costliest raw material,the plantation wouldprovide the group with a platform to better manage themarket dynamics relating to demand, supply and cost of red sandalwood. RedSandalwood has been valued and treasured for many years for its heartwood,carving, medical and religious qualities. The maturity period for redsandalwood trees is 12 years. The Red sandalwood trees grown through the bestpractices adopted by the organization.The scientific name for red sandalwood isPterocarpus santalinus is a species of Pterocarpus native toIndia. Redsandalwood is a tree. The wood at the center of the trunk (heartwood) is usedas medicine. Red sandalwood is used for treating digestivetract problems, fluidretention, and coughs; and for “blood purification.” Don’t confuse redsandalwood (Pterocarpus santalinus) with white sandalwood (Santalumalbum).Indians have been long deprived of this precious cash crop called"Red Sandalwood”. This wild tree yields Crores of rupees however needsleast human care for its growth.Indiais one among the only six countries .It is found only in southIndia.which has the favorable soil and climateconditions to grow Red Sandalwood and was once a huge supplier to the rest ofthe world.However in the recent past the situation became such thatIndiahad to import sandalwood from other countries as the natural resource from theforests had almost come to an extinct. Finally in the year 2008, with Government of India amending its act and giving permissions to cultivateSandalwood has opened doors for individuals and co-operatebodies to relish the rich outcome of cultivating this wild crop. Thistrees when grown under organized cultivation with plantation experts and dripirrigation, fetch maximum results.The Facts About Red Sandalwood.The facts about Red Sandalwood farming is well known to the Indianfarmers, however its farming is still avoided as our farmers need farminglands, equipments and the finance to survive throughout the cultivation periodwhich lasts around 12 years. The financial situation of our farmers is notsomething new to us. Government support has been minimal and providingsubsidies is not good enough for this cause. This leaves our farmers helplessand prone to cultivate small alternate crops or further more sell their landand do petty jobs for survival. On the other hand we have the employee classwho can easily afford this small farming expenses however choose to stay awayfrom farming as they have very little or no farming knowledge or still further,do not wish to get into farming What Can Be Done? It’s time to look into thefacts and analyze the scope of Red Sandalwood farming and it’s also time forthe Landlords and the developers to get together creating a win –win situationfor both the communities. To bridge the gap between the landlords and thedevelopers of people mainly Biologists and Nature lovers have designed thisproject called SVS Agro Farms Developers cultivating Red sandalwood crop, thusreducing the risk factors and encouraging more and more small, medium investorsto come forward and join this project. SVS Agro Farms Developers has kept theproject easily affordable to most of the communities, thus trying to benefitall and serve better.
类似的紫檀农场还有若干，数量没有统计，通讯地址均是海得拉巴，网站已无法正常登陆，后面不再列述。1.《紫檀香及其混伪品的鉴别》(1993,白武龙)、
2.《药用紫檀香考辨》(1998,5,李书渊)、
2.《檀香、紫檀香、降香及苏木的紫外光谱和薄层色谱鉴别》 (1999,侯世海)、
2.《中华本草》(1999,9)、
2.《紫外光谱法测定蒙药紫檀香总黄酮的含量》(2012,10,朱明,王静,张小宁)、
2.《蒙药紫檀香药材质量评价研究现状》(2014,10,朱明,王静,张小宁)。
2.《红木》GB/T 18107-2000(2000,8,1发布)
3.《Pterocarpus santalinus (Red Sanders) an Endemic, Endangered Tree of India: Current Status, Improvement and the Future》(2014,A.N. Arunkumar and G. Joshi)
4.《世界紫檀属树种及其在我国的引种前景》（2000,曾杰,陈青度,李小梅）
5.《檀香紫檀资源培育与利用研究进展》(陈仁利,曾 杰)
6.《中国热带主要经济树木栽培技术》(2001,周铁峰)
7.《A manual of indian timbers》(1902,James Sykes Gamble)
本文所用图片有如下几个来源：THE WOOD DATABASE网站、《紫檀》插图的翻拍、及@紫金紫檀、@wml_rail 等几位朋友。凡注为“互联网”者均为网上的下载或朋友间的拷贝，这部分图片因为无法找到原始出处，故无法一一具名。本文采用的所有图片的版权属于原作者，如涉及侵权，请联系笔者将其删除。笔者在此向图片所有者一并表示谢意和敬意，谢谢!
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