Website/Catalog  (29 Jan 2010)  Includes photo(s).
 
Paeonia suffruticosa Andr. var. papaveracea
Papaveracea has nearly single, white flowers with a purple blotch at the base of the petals.  Such a plant is figured beautifully in Curtis’s Botanical Magazine.  The flowers apparently tended to become more double in succeeding generations.  [Hortus, BM t.2175/1820, Don].  See Paeonia suffruticosa Andr. for more information.

Horticultural & Botanical History
‘Paeonia Moutan var. papaveraceae, is no doubt the normal form of the Tree Paeony, and all the double-flowered varieties of P. Moutan are evidently the offspring of this paternal stock, and since it has sported so freely into beautiful varieties in this country there can be no doubt that the beautiful kinds which Mr. Fortune and other parties tell us are grown at Shanghai have mostly sprung from the same parent stock.’  [Gard. Chron 1856]. 
‘It may perhaps be considered as the parent plant of all the double varieties.’  [LBC no.547/1821]. 
‘The plant which has been adopted as the type of the species, in consequence of its having single, or rather nearly single flowers, has been always called Papaveracea, not because its petals are like those of the Poppy, but because its germens [...] resemble a capsule of the large Papaver somniferum.  The P. moutan papaveracea was imported by Captain James Pendergras, in the Hope East Indiaman, for Sir Abraham Hume, in 1802, and the plant first blossomed in 1806.  I do not believe that any other plant of the variety has been brought from China; and if the fact be so, Sir Abraham Hume’s was the parent of the whole stock now in Europe.  The flowers in some seasons, and especially of late years, have been semi-double; when the plant was younger they were more single, but seldom had as few as five petals’  [Clericus in FC p.44/1842].  ABR pl.463/1807.

History at Camden Park
Listed in all published catalogues [T.743/1843].

Article (magazine)  (2001)  
 
Haw and Lauener (1990) treated P. papaveracea as a cultivar of P. suffruticosa. Although the flowers of P. yananensis and P. papaveracea show considerable similarity, there are very clear differences in the leaves. Those of P. yananensis often have 11-15 leaflets, while those of P. papaveracea never have more than nine. The shape of the leaflets is also different. The foliage of P. papaveracea is absolutely typical of P. suffruticosa, closely similar to that of most P. suffruticosa cultivars. It does not, therefore, seem reasonable to consider these two taxa identical. P. yananensis is probably the result of hybridisation only between P. rockii and P. spontanea, while P. papaveracea is a cultivar of P. suffruticosa, a complex hybrid with not only R rockii and P. spontanea but also P. ostii in the parentage

Article (magazine)  (Jan 1955)  Page(s) 10 - 11.  
 
In 1802, Capt. James Prendergast of the Hope, brought from China a single or semi-double white with large purple spots at the base. It flowered in the garden of Sir Abraham Hume of Wormley Bury, Herts., in 1806(7). Botanists considered it to be the true species and they called it P. papaveracea , and later P. moutan papaveracea, not, as is commonly supposed, on account of its resemblance to the flower of a poppy, but because one of its microscopic parts resembled the seed vessel of the common European poppy. 

Website/Catalog  (1921)  Page(s) 68.  
 
Paeonia arborea...papaveracea. Large, double, lilac-pink, center flecked purple...1 piece M 15,00-25,00

Book  (1917)  Page(s) 200-201.  
 
....in 1850 there were a dozen distinct kinds in cultivation in England. Some of these had probably been raised from seed obtained from the three original varieties imported. The Earl of Mount Morris and the Earl of Sandwich both took a great interest in the tree peony and produced several distinct sorts from the Papaveracea.

Book  (1917)  Page(s) 202-203.  
 
In 1826, a plant of P. moutan, var. papavaracea, was imported from England by William Lathe of Cambridgeport— probably a wise and public-spirited move, for if ever a place (from its present appearance) needed brightening up it must have been Cambridgeport.
It is an historical fact that this peony was later moved from Cambridgeport to the place of J. P. Cushing, Watertown, Mass.
In 1828 the catalogue of John Bartram lists the same variety, adding " poppy flowered tree pæony," but without price, and " P. moutan rosea, rose coloured," at five dollars.

Magazine  (8 Jul 1899)  Page(s) 300.  
 
Les botanistes et les horticulteurs ont distingué dans le P. Moutan deux races principales :
1° Paeonia Moutan var. papaveracea.
2° Paeonia Moutan var. rosea.
La première, remarquable par ses huit ou dix pétales, d’un blanc pur ou plus ou moins teinté de rose, avec une ample macule pourpre à l’onglet; la seconde, par des fleurs d'un rose plus ou moins intense, maculées aux onglets, ou à
macule peu marquée. Cette dernière a aussi des feuilles plus grandes, des sépales plus larges. Toutes deux, dit-on, n’auraient été introduites en France qu’en 1803. Il serait à peu près impossible de retrouver aujourd’hui les deux
types que nous venons de citer. ...Dans l’espèce type et ses variétés (papav. et rosea), au centre des 5 à 10 pétales, est une couronne d’innombrables étamines, à filaments roses ou blancs, à anthères d’un jaune d’or, entourant 2 à 9 ovaires velus, terminés par les stigmates persistants, et plus ou moins enveloppés par un urcéole charnu, coloré comme les pétales.

Book  (1898)  Page(s) 211-212.  
 
J. Sabine, in his treatise on Paeonia Moutan, Trans. Hort. Soc. VI, 1826 reports:
p. 469. The Paeonia Moutan papaveracea was imported 1802 for Sir A. Hume, by Capt. Pendergrass in the "Hope" E. I. man..
In Loudon's Arbor. et Frut. Brit. I (1838) 254, we read: "North of London the largest plant (Moutan papaveracea) in the country is at the seat of Sir Abraham Hume, at Wormleybury, in Hertfordshire. It is 7 feet high, and forms a bush 14 feet in diam., after having been planted thirty years. It stands the winter, in general, very well. In 1835 this plant brought 320 flowers to perfection; but it has been known to bear three times that number".

Magazine  (22 Jan 1887)  Page(s) 76-7.  Includes photo(s).
 
The Tree Pæony. 
A hundred years have elapsed since the first living plant of the Tree Pæony was brought to this country from the gardens at Canton, and the honour of introducing it is due to Sir Joseph Banks.  He had heard of its existence in Chinese gardens, and engaged a Mr. Duncan, who was attached to the East India Company's service, to obtain plants of it and send them home.  Through Mr. Duncan's exertions the first live Moutan was received at Kew in 1787.  For 1400 years the Tree Pæony is said to have been cultivated by the Chinese, who would have us believe that it originated from Pæonia albiflora, also a native of China.  But such is not a fact, for it is proved beyond doubt that the Moutan is a true wild shrub, indigenous not to the southern parts of China, but to the northern provinces of Ho-Nan and Nan-Kin, where it inhabits mountainous regions and whence it was brought to Canton.  For countless generations Chinese gardeners have occupied themselves in raising new varieties of Hoa-Ouang (the king of flowers), as they call this Pæony, and fifty years ago Anderson asserted that they possessed no fewer than 250 distinct sorts representing all the colours which Pæonies are capable of producing.  They have crimsons of every shade to nearly black, whites, yellows, purples, roses, and even blues.  These are said to be all self-coloured, for, singularly enough, the Chinese reject variegated flowers, regarding them as unnatural.  Some varieties they call Pe-Leang- Kin (a hundred ounces of gold), in allusion to their great value.  In 1794 a second variety was introduced by a Mr. Greville; this was named rosea, the flowers being of a deep rose-pink colour, while those of Sir Joseph Bank's plant were blush-pink and double.  In 1806 a third variety was introduced, and this, because its flowers were single, was and still is considered to be the type or wild plant.  It was named papaveracea, the Poppy-flowered Pæony, on account of the capsule being like that of a Poppy by reason of the seed vessels being enclosed in a membraneous disc.  The accompanying woodcut well illustrates this variety, which is white with heavy crimson blotches at the bases of the petals.  The above varieties, viz., Banksi, rosea, and papaveracea, are all that are described in Anderson's "Monograph of the Genus Pæonia", given in vol. vi. of the Horticultural Society's Transactions (1838)...

Website/Catalog  (1860)  Page(s) 26.  
 
Chinese Tree Pæonies. — Pæonia Moutan.
These are the most splendid and showy of all flowering shrubs, and among the most rare.
The flowers are mostly fragrant, and all are double, unless denoted otherwise.  They are perfectly hardy, and will withstand the winters of our most northern States and the Canadas.  They bloom in May, ten to fifteen days before the Chinese Herbaceous varieties.
Extra large plants, of five and six years' growth, of Nos. 1 and 2, can be supplied at $2 and $3 each; and also of many other varieties, at $3, and others at $5 and upwards.
2. Papaveracea...  Very large, single white, with crimson centre...  75¢ to $1.00