Article (magazine)  (2001)  
 
KEY TO VARIETIES
1. Shrub more than 1 m tall (usually up to c. 1.8 m):...... 1. var. delavayi
1. Shrub or subshrub up to not more than 1 m tall:..... 2. var. angustiloba

1. var. delavayi
KEY TO FORMAS
1. Petals entirely orange or yellow to greenish-yellow, or yellow blotched with dark red at the base, or yellow with a red margin:..... 1b. var. delavayi f. lutea

1b. var. delavayi f. lutea (Delavay ex. Franch.) S. G. Haw, stat. nov. Typus: China, NW Yunnan, Eryuan County, Mt Hea Chan Men, 25 May 1883, Delavay s.n. (lectotype, P - n.v., isolectotype, K); Syn. P. lutea Delavay ex Franch., Bull. Soc. Bot. Fr. 33: 382 (1886)....Included here are all the taller-growing variants of the species with predominantly yellow or orange flowers. Orange-flowered plants may be the result of hybridisation between plants with yellow and red flowers and their inclusion here is therefore more or less arbitrary. P. delavayi var. lutea of gardens belongs here. As far as I can ascertain, there is no clear record of white-flowered plants tall enough to be placed with this variety.

Book  (Jan 2000)  Page(s) 49-50.  
 
Stern's second subsection of tree peonies, subsection Delavayanae, includes several species discovered in the mountains of Southwestern China toward the end of the 19th century. In it, he identified and defined the following species:
....Paeonia lutea Delavayi ex Franchet var. lutea
This is a native of Yunnan province, most abundant in the mountains above Dali. It differs from previous species in the color of its flowers, which are a clear lemon-yellow. It varies greatly in size over the range where it has been found, from 3 feet to more than 6 feet in height. The small flowers, 2-3 inches in diameter, are usually hidden by the foliage. Once again, the species has no real landscape value, but its appealing lemonlike fragrance is often passed on to its hybrid offspring. Hardy to zone 5, though it seldom blooms in climates colder than zones 7 or 8; even then it is sparsely floriferous at best. Diploid (10 chromosomes).

Book  (Jan 2000)  Page(s) 21, 22.  Includes photo(s).

Book  (Jan 1999)  Page(s) 632.  Includes photo(s).
 
P. lutea ('Yellow Tree Peony') from western China... introduced to the West in the late nineteenth century

Book  (Jan 1999)  Page(s) 19.  
 
Paeonia lutea another of Père Delavay's 1884 discoveries, found on Mount Hea Chan Men in Yunnan and in the mountains above Dali at overlapping and slightly higher altitudes than P. delavayi. The plants are similar in some ways, and may be two forms of the same species. They can never be confused when in flower, for P. lutea lives up to its name with single flowers of bright, clear yellow. They have the bonus of a lemony scent but they share with P. delavayi a reluctance to flower in climates below Zone 7.

Book  (1999)  Page(s) 137.  
 
Paeonia lutea, China, Tibet, 1949

Article (magazine)  (Jan 1955)  Page(s) 12-13.  
 
Paeonia lutea Delavay ex Franchet, Bull. Soc. Bot., France, 1886.
Syn. P. delavayi lutea Finet. & Gagnepain, 1904. Marquand, 1929.
P. lutea superba Hort., 1908.
Yellow like a large buttercup or yellow with reddish blotches at base and commonly called the yellow tree peony. Has a lilylike fragrance. Two to two and a half inches, in cultivation, sometimes to three inches. Very variable, usually about three feet, but Kingdon Ward reported six to eight feet. Delavay discovered it in Yunnan 1883 in spruce forests at eleven to thirteen thousand feet. Sent to Paris Museum of Natural History in 1886, but it has also been referred to as the wild yellow tree peony of southern China. It flowered in 1892 and was exhibited by Professor Maxime Cornu. The segments and lobes of the leaves are mostly three-fourths to one and a quarter inches wide. The foliage is handsome and fernlike.

Article (magazine)  (Jan 1955)  Page(s) 21-22.  
 
Compared to the long history of the Moutan peony, the yellow and maroon species and botanical varieties of the Delavay Group are of comparatively recent discovery and introduction. The two first known, Paeonia lutea and P. delavayi, were discovered in China by the French Jesuit, Father Jean Marie Delavay. He sent them to Paris in the late 1880's, and they bloomed there in the early nineties. They were first de cribed as distinct species by the French botanist, Franchet. Later botanists considered P. lutea to be merely a botanical variety of P. delavayi. Rehder, in his Manual of Cultivated Trees and Shrubs, felt that the differences were sufficient for each to be regarded as a species....Superficially, none of these plants seems to give promise of any value for breeding. Indeed, the first flowers of P. lutea that were shown in Paris seemed so insignificant that one of the greatest horticulturists of the time, M. Maxime Cornu, publicly remarked that it would never amount to anything. We wonder if he has turned over in his grave every time one of the new hybrids has made its debut! What a pity he did not live to see even the one that his colleague, Professor Louis Henry of the Paris Museum of Natural History, raised and named in his honor, 'Souvenir de Maxime Cornu.'
 

Article (magazine)  (Jan 1955)  Page(s) 58.  
 
Alphabetical Check List of Tree Peony Names In  Public Collections And/or Available in Nurseries 1954-1955
lutea, [Gardens] Scott Foundation, University of Washington Arboretum, see under species

Website/Catalog  (1935)  Page(s) 23.  
 
Pivoines arborescentes....Pæonia lutea.
Très intéressante espèce chinoiseà petites fleurs d'un jaune bouton d'or brillant. La pièce: 7 fr. 50.