又一个宣称投资紫檀种植的广告，公司地址仍在海德拉巴。http://www.srinidhihomes.in/ongoing-projects.html

老新闻，2002年的，安德拉邦森林发展公司计划增加紫檀种植规模：http://www.thehindubusinessline.com/2002/08/05/stories/2002080500841300.htm
APFDC plans to raise red sanders as plantation crop
Our Bureau
Despite a ban on exploitation and sale, good quality red sanders fetched any price between Rs 3 lakh and Rs 4 lakh per tonne in the global market.
HYDERABAD, Aug. 4
FOR years red sanders, unique to the forest areas of Cuddapah, Chittoor and Nellore districts in Andhra Pradesh, has been the much sought after wood by illegal traders, who smuggled it to distant lands, especially Japan.
Now through the sustained efforts of the Andhra Pradesh State Forest Department, there is hope of it being raised as a plantation species.
Efforts were on to raise nurseries of this species and promote plantations in the near future, said Dr K. Ramakrishna Rao, General Manger of the Andhra Pradesh Forest Development Corporation (APFDC), under the Forest Department.
Simultaneously, research initiatives are under way to exploit its potential application in soaps, dyes, toys etc. Despite a ban on exploitation and sale, good quality red sanders fetched any price between Rs 3 lakh and Rs 4 lakh per tonne in the global market, while the inferior type was sold as fuel wood like other timbers, he told Business Line.
Red sanders is endemic to only these three districts and is a slow-growing tree. If raised as a plantation crop, the quality of the wood is not often good. Therefore more efforts were needed and the forest department was at it, he said. The demand for red sanders exists in Japan and 40 other countries.
Since regular harvest of red sanders has been banned several years ago, the illegal felling and smuggling have occurred periodically. The State Government's agencies have seized large quantities of wood from smugglers. Such seizures over the past decade have yielded nearly 1,800 tonnes of the material, for which the FDC has been appointed by the State Government as the main selling agent.
The Corporation segregates and sells the material in the global market. Interestingly, Japan alone has procured 200 tonnes in recent times. Red sanders was used in Japan mainly for making musical instruments, he said.
It is estimated that it grows in about 50,000 hectares of forest area in the three districts. With the potential for using red sanders as an important input in the manufacture of agarbathis, as a natural dye (research is even on in Germany and France),and in the toy industry, efforts to make it a plantation crop are, indeed, promising.

楼上有些图片里的木头，如果不是阿三站在边上，说是血檀一点问题没有。
最后一图，安德拉邦某农场里接近成熟的紫檀人工林。估计只有十几二十年的树龄。

另外，印度人写的一篇文章里有如下文字：
Heartwood of Red Sanders has high demand in domestic as well as international market and the wavy grained wood is valued.
There are two types of wood that is popular in trade, one is wavy or ripple grained and the other is straight grained. The wavy grained wood has a huge demand in the international market and is primarily exported to Japan for manufacturing a special musical instrument called as ‘Shamisen’ a three stringed lute used in classical music as the wavy grained wood is supposed to have superior acoustic qualities.
大意是紫檀分波纹和直纹两种，波纹很受欢迎且较贵，大量出口日本制作三味线。

网页还好，有图片帮助，看几行字就知道大意。那些PDF文件拿过来才明白自己的英文水平有多烂……
其实外国人把紫檀的生物特性已经研究得非常透彻了，国人很少去检索，找了的也多数看不懂。

英文资料里提及的紫檀木消费者，首当其冲是日本，中国总排在日本后面，有的资料甚者只说日本和南亚本地制药，完全忽略中国。既然很多琴料被认为是质地非常好的紫檀木，那么明清时期的紫檀木应该还是檀香紫檀。
内地包括北京远离热带硬木的产地，也不是进口木材入境之处，所以出现很多臆测说法，而且传得很快。

印度的资料说印度原产的紫檀属植物只有4种，安达曼紫檀、囊状紫檀、印度紫檀和檀香紫檀。比东南亚少，更比非洲少。在印度和斯里兰卡，紫檀木主要用作染料和药材。说到药材，印度人传给藏族人，藏族人又传给蒙古人，成为蒙医的一味药材。

1996年登载于印度某期刊的一篇极好的文章，绝对颠覆很多人的思维习惯！下载全文需要付50印度卢比，不足人民币5块钱，可惜我不知道怎么付钱。
Identification of Wavy Grained Red Sanders (Pterocarpus santalinus) at Nursery Stage
M. S. Rawat , D. P. Uniyal
Abstract
Highly wavy grained wood of Red Sanders fetches fabulous prices in the export market, particularly Japan. While the straight grained or normal grained is sold at a very cheap rate. Hence, to increase the frequency of highly wavy grained trees it is necessary to multiply them for large scale plantations, directly or indirectly. A method has been suggested to identify the highly wavy grained plants at nursery stage.
在育苗期确认波纹紫檀的方法
M. S. Rawat , D. P. Uniyal
波纹明显的紫檀木在国际出口市场上能卖出极好的价钱，特别是卖给日本时，直纹或普通纹理的紫檀卖得很贱。这样，大规模种植紫檀时有必要增加波纹明显的树的比例。我们提出一种在育苗期识别出波纹明显的植株的办法。

有印度学者在1976年就报道了波纹紫檀木所占比例低于1%，并且是遗传因素，而不是生长环境所致，在野生林和人工林中具有同样的比例。
……不用再探讨方便面纹理是什么环境下长出来的了，跟中国人里的自来卷一样，基因所致。

Studies on Variation in Fibre Morphology in Wavy-grained and Straight Grained Trees of Red Sanders
S. Kedharnath , M. S. Rawat
Abstract
Wood samples extracted at breast height from 7 wavy-grained and 3 normal grained trees in red sanders were examined for possible variation in fibre morphology from pith to periphery. The data obtained was analysed by an analysis of variance using the mean values and grouping the trees into two groups of wavy and non-wavy, into three groups of highly wavy, medium wavy and non-wavy and finally without any grouping. The mean value of lumen diameter appeared to be larger in the wavy grained trees as compared to that from normal grained trees and difference between the mean values was found to be very highly significant. This is likely to be a useful character for screening the saplings if it is confirmed after an examination of a larger number of trees.
又一篇付不了卢比的文章，作者好像专门研究紫檀的波纹，发表不止一篇文章。摘要大意是从胸部高度采集了7个波纹和3个直纹的紫檀木样进行研究，波纹木材的平均管孔直径大于直纹的，差别还不小。这个特点也许对树苗的筛选有用处。

檀香紫檀原生范围只有5160平方公里，可能比降香黄檀的自然分布区还小，而且是热带稀树林地，不是典型的森林。如果没有人工种植，可能现在没多少国人能遇上紫檀木。

看到一篇2011年发表的印度论文，研究不同年龄人工林的直径和心材比例，可惜没有清晰的配图。研究时间应该是2008年，研究对象是 卡纳塔克邦 班加罗尔周边人工种植的紫檀树林，有两个地方，第一个种了20年，第二个种了45年（1963年开始）。研究方法是在树干上钻孔取样。
20年树龄的取样130株（长出心材的有98株）。
胸高处树干周长平均49.84cm，最小25cm，最大79cm。
树皮比例（中国木材学教材里按面积计算，印度应该也一样）平均19.14%，最小10.59%，最大38.93%。
边材比例平均54.52%，最小22.86%，最大89.51%。
心材比例平均26.34%，最小0%，最大65.71%。
长出心材的98株树木，胸高处树干周长平均52.36cm，最小32cm，最大79cm。
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45年数量的取样98株（长出心材的有95株）。
胸高处树干周长平均73.83cm，最小37cm，最大111cm。
树皮比例平均8.88%，最小3.81%，最大20.26%。
边材比例平均30.75%，最小10.7%，最大87.02%。
心材比例平均60.37%，最小0%，最大81.95%。
单独统计长出心材的95株树木：
胸高处树干周长平均74.67cm，最小44cm，最大444cm。
树皮比例平均8.64%，最小3.81%，最大14.63%。
边材比例平均29.08%，最小10.7%，最大80.44%。
心材比例平均62.88%，最小6.18%，最大81.95%。
——作者的结论是，同一地域生长的檀香紫檀树木长出心材的情况有很大差异，选育良种的时机可以选在树龄20~25年时（意思是此时心材比例的差异很大，把心材比例大的树木留下，接的种子用于继续配置新树苗，从而优选出心材形成快的品种）。

看了一些印度人的文章，感觉大部分作者区分quality（优质）和non-quality紫檀木的标准就是有无wavy grain(波纹)，不考虑木材密度，至于油性这种难以衡量的性质更无人提及。
只有一篇文章提到：
Red Sander plants are broadly classified as a quality and non-quality variety. It is interesting to note that quality plants are characterized by wavy grain texture with intense red color and the non-quality are characterized by straight grain texture with light Red color.
“紫檀木大体分为优质和普通两种，优质紫檀的特点是波纹质地且具有浓烈的红色，普通紫檀是直纹质地且具有偏淡的红色”
——算是勉强跟油性挂点勾。