Book  (1999)  Page(s) 58.  
 
Every year the first peony to flower in my garden is 'Early Bird', a well and truly named triple hybrid by Dr. Saunders, dating from 1939. From a hybrid betweeen Paeonia emodi and P. veitchii a further cross was made with P. tenuifolia which has narrow, even thread-like dissections of the foliage, inherited by 'Early Bird'. To this charm is added the same species' rich crimson colouring. It is a wonderful sight with Narcissus poeticus recurvus.

Magazine  (1961)  Page(s) 46.  
 
We asked him which variety was the first to bloom and he informed us that it was Saunders' Early Bird, a fine descendant of tenuifolia

Website/Catalog  (1955)  Page(s) 2.  
 
Herbaceous Peonies
Hybrids.
Woodwardi x tenuifolia
Earlybird. Sold as a strain. Among the first peonies to bloom. Handsome little plants with finely-cut foliage and an abundance of bright crimson flowers. $5