title: How do I just remove one of the two legends in GGPLOT
body: <p>I have the following code:</p>
  
  <pre><code>library(ggplot2)
  
  df     &lt;- data.frame(iris)                   # iris dataset
  pca    &lt;- prcomp(df[,1:4], retx=T, scale.=T) # scaled pca [exclude species col]
  scores &lt;- pca$x[,1:3]                        # scores for first three PC's
  
  # k-means clustering [assume 3 clusters]
  km     &lt;- kmeans(scores, centers=3, nstart=5)
  ggdata &lt;- data.frame(scores, Cluster=km$cluster, Species=df$Species)
  
  # stat_ellipse is not part of the base ggplot package
  source("https://raw.githubusercontent.com/tidyverse/ggplot2/master/R/stat-ellipse.R")
  
  
  ggplot(ggdata) +
    geom_point(aes(x=PC1, y=PC2, color=factor(Species)), size=5, shape=20) +
    stat_ellipse(aes(x=PC1,y=PC2,fill=factor(Species)),
                 geom="polygon", level=0.95, alpha=0.2) +
    guides(color=guide_legend("Species"),fill=guide_legend("Cluster"))
  </code></pre>
  
  <p>Which produces this:</p>
  
  <p><a href="https://i.stack.imgur.com/NrdEb.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/NrdEb.jpg" alt="enter image description here"></a></p>
  
  <p>As stated in that picture how do I just remove 'Cluster' legend?</p>