Website/Catalog  (29 Jan 2010)  Includes photo(s).
 
Paeonia officinalis L. var. L. var. Sabini
See Paeonia officinalis L. for a description of the species.  Sabini has single, very dark purple flowers.  [PD].

Horticultural & Botanical History
‘The Paeonia officinalis is a plant which has been long universally known.  It was cultivated before the time of Pliny, and has had various medical virtues ascribed to it, which seem to have been all superseded.  The single variety was not known in this country in modern times till discovered by Mr. Sabine, in an old garden in Hertfordshire. […] It is a native of hilly woods in the South of Europe, and some parts of Asia.  It flowers profusely in June, and is a great ornament to the gardens.’  [LBC no.1075/1825].  The flower shown here is bright red rather than purple.

History at Camden Park
Listed in the 1850 and 1857 catalogues [B.397/1850].

Website/Catalog  (1936)  Page(s) 12.  
 
May-Flowering Pæonies.
Herbaceous species and varieties.
Single-flowered unless otherwise described.
Officinalis Sabini. Fine red....3/6

Book  (1917)  Page(s) 228.  
 
Officinalis....Varieties:....Sabini, single red, yellow stamens and anthers.

Magazine  (10 Jun 1893)  Page(s) 642.  
 
Single Pæonies.
These are now mostly out of bloom, but in spite of the dry weather, they made a fine display during last month, and might have been seen at their best as early as the first week in May, in the nursery of Messrs. Barr & Son, Long Ditton, Surrey. [...]
The flowers of Pæonia Sabinii are brilliant red, and consist of about eight petals. 

Magazine  (6 Jul 1889)  Page(s) 9.  
 
Single-flowered Pæonies.
A few good single types are—
Sabini.—A variety of officinalis, the colour rich crimson, and the stamens yellow.

Magazine  (4 Jun 1887)  Page(s) 513.  
 
P. officinalis var. Sabini. — It appears that a few years previous to Anderson's "Monograph of the Pæonies", in the 12th number of the Linnean Transactions, the single-flowered P. officinalis had become so rare in gardens, that it was scarcely known to writers of that period; in fact, a single-flowered form was not believed to exist in a living state until Mr. Sabine had the fortune to find a plant in the corner of an obscure old garden in Hertfordshire.  It differs but slightly from the type, the flowers exactly corresponding in colour to those of the double red, opening a few days earlier, and not lasting nearly so long in bloom; the leaves are much less undulated than the type, the plant being more robust in habit

Website/Catalog  (1884)  Page(s) 36.  
 
Single Hardy Paeonias.
1638 Officinale sabini, scarlet, 2s. 6d.

Magazine  (Aug 1837)  Page(s) 285.  
 
Some Remarks on the herbaceous Paeonies, together with a description of most of the Species and Varieties, and a few observations upon their Propagation, Cultivation, &c. By the Conductor. (p. 283-292)
P. officinàlis var. Sabìni.—One of the most showy of all the single ones: the flowers are extremely large, of a very brilliant crimson, with bright yellow stamens and anthers: in foliage and habit just like the last: in flower from the 4th to the 12th of June. It is a variety which should be in every garden.

Website/Catalog  (1837)  Page(s) 66.  
 
Pæonies. Pivoines.
1 Sabine's crimson officinal...Pæonia officinalis, sabini...75¢ to $1 00

Magazine  (Apr 1836)  Page(s) Vol. 18, p. 271.  
 
Liste des Pivoines cultivées chez le prince de Salm-Dyck.
PIVOINE, Pœonia, LINN.
II. TIGES HERBACÉES.
B. UNIFLORES. 7. LOBÉES.
elegans, Sab.
fulgida, Sab.
lobata , Desf. ; lusitanica , Mill.
— id. flore coccineo, Hort. Dyck.
— id. staminibus elegantissimis, Hort. Dyck.
officinalis , Retz.
— angustissima, Hort. Dyck.
— angustifolia , Hort. Dyck,
— glaucescens, Hort. Dyck.
— intermedia, Sab. 
— imbricata, Sab. 
— blanda , Anders. 
— rosea, Anders. 
— id. flore pleno , Hort. Dyck. 
— Sabini , Anders. 
— anemoneflora , Nob. 
— rubra , Anders. 
— atrorubens, Sab. 
— id. fol. variegatis. 
— carnescens, Anders. 
— albicans, Anders. 
— alba , Hort. Dyck.