代码如下：
pca.plot <- read.csv("data.csv",row.names=1, header=T)
Lauraceae <- pca.plot[1:14,]
Fagaceae <- pca.plot[15:20,]
Myrtaceae <- pca.plot[21:27,]
Rubiaceae <- pca.plot[28:37,]
ggplot(Lauraceae, aes(PC1, PC2)) + geom_point(size = 6.0, colour = "#EE1289", shape = 18) +
  geom_point(data = Fagaceae, size = 5, col = "#1874CD", shape = 16) +
  geom_point(data = Myrtaceae, size = 4.5, col = "#228B22", shape = 15) +
  geom_point(data = Rubiaceae, size = 5, col = "#7EC0EE", shape = 17) +


因为需要指定每个类型点的颜色和性状，所以只好手动一层层加上去，再定义，但是这样画出来的图就不显示图例了，恳请坛友帮助如何显示图例~谢谢！后续还需要添加更多的Family，如果想指定这些Family的点性状颜色，有没有更简单的方法，不用手动一个个添加的？

数据如下：

Family	PC1	PC2
Lauraceae	-0.07802	0.281613
Lauraceae	-0.18107	0.378589
Lauraceae	-0.65634	-0.36388
Lauraceae	0.13175	0.012919
Lauraceae	-0.28589	-0.36197
Lauraceae	0.20609	0.198577
Lauraceae	-0.46091	0.11853
Lauraceae	-0.77426	0.357975
Lauraceae	-0.81335	0.099304
Lauraceae	-0.02209	-0.64762
Lauraceae	-0.5823	-0.0268
Lauraceae	-0.24159	-0.67401
Lauraceae	-0.62573	0.370096
Lauraceae	-0.47904	0.312894
Fagaceae	-0.70432	-0.10668
Fagaceae	-0.41688	-0.62105
Fagaceae	-0.41807	-0.44478
Fagaceae	-1.07812	0.231227
Fagaceae	-0.64854	-0.3509
Fagaceae	-0.88722	-0.06045
Myrtaceae	0.12592	-0.38653
Myrtaceae	-0.2339	0.707437
Myrtaceae	-0.30893	-0.01912
Myrtaceae	-0.3187	-0.31963
Myrtaceae	-0.18848	-0.88771
Myrtaceae	-0.62694	-0.69233
Myrtaceae	-0.26791	-0.973
Rubiaceae	-0.20898	-0.73792
Rubiaceae	0.03932	0.163706
Rubiaceae	-0.362	-0.15984
Rubiaceae	0.84551	0.329486
Rubiaceae	0.24983	-0.38807
Rubiaceae	0.77355	0.346762
Rubiaceae	0.19266	-0.19431
Rubiaceae	0.19393	0.024911
Rubiaceae	0.4097	0.081883
Rubiaceae	0.46633	-0.41123