A dwarf, subshrubby deciduous plant with a short woody stem; entirely glabrous. Leaves leathery, 12 to 15 in. long, strongly nerved, deep green above, glaucous beneath, ternate, with the three divisions pinnatifid and deeply cut at the margin. Outer sepals narrow-lanceolate, acuminate, inner ones roundish, concave, yellowish green. Petals six to ten, golden yellow, roundish concave, with usually crenate margins and sometimes with a carmine stain at the base. The flower is 21⁄2 in. across, and is sometimes slightly ‘double’, both in the wild state and the cultivated. Seed-vessels three or four, glabrous. Bot. Mag., t. 7788.
Native of the mountains of S.W. China; discovered in Yunnan by the French missionary Delavay, who also introduced it to Europe by means of seeds sent to the garden of the Paris Museum in 1887. A plant obtained from France flowered in the Temperate House at Kew in 1900 and from this the figure in the Botanical Magazine was made. Three years later P. lutea received a First Class Certificate.
P. lutea, in the form originally introduced, is not so decidedly a shrub as P. suffruticosa, but forms a short, woody stem up to 3 ft high (sometimes slightly taller). It is a beautiful paeony, though in some forms the flowers are apt to be hidden by the foliage. They are borne in June. It is now rare in gardens, having been displaced by the more vigorous var. ludlowii.
Only three plants were raised from the seeds sent by Delavay. One of these differed from the others in its more robust habit and in having flowers up to 31⁄2 in. wide, with nine to eleven petals, reddish maroon stamens, and bronzy young foliage. This was propagated by Lemoine and named ‘Superba’.
var. ludlowii Stern & Taylor – This differs in its larger flowers up to 4 or 5 in. across, with more spreading petals, and with only one or two fertile carpels. It is also of larger stature, attaining in cultivation a height of 6 to 8 ft and as much in width. It flowers in May, three weeks or so before typical P. lutea. So far as is known, it is confined to a small area of S.E. Tibet near the Tsangpo gorges, at 9,000 to 11,000 ft. It was introduced by Ludlow and Sherriff in 1936 and reintroduced on later expeditions to the same area. At first it was known in gardens as the Tibetan or Ludlow and Sherriff form of P. lutea and was first distinguished botanically in 1953, in the article accompanying the plate in the Botanical Magazine (n.s., t. 209).
The var. ludlowii makes a splendid foliage plant, always of symmetrical and dense habit if not crowded. But on some plants the flowers are sparsely borne or concealed by the foliage. These may be growing in a too rich or too moist soil; or seedling variation may be the explanation, for this variety is always increased by seeds. At its best it makes a fine display. A.M. 1957.
P. × lemoinei Rehd. – Here belong hybrids between P. lutea and the moutan, P. suffruticosa. The first, and still the best known of these, were raised by Louis Henry in the garden of the Paris Museum, and by Messrs Lemoine of Nancy. Many others were raised later in the USA by Prof. A. P. Saunders. The following are available in commerce or have received awards from the Royal Horticultural Society:
‘Alice harding’. – flowers lemon-yellow, fully double.
‘Argosy’. – Flowers 7 in. across; petals primrose-yellow blotched carmine at the base. This is one of the Saunders hybrids and was considered by Sir Frederick Stern to be the best of the single yellows. It received a First Class Certificate when shown by him on June 6, 1956, but seems to be scarce in commerce.
‘Chromatella’. – A sport from ‘Souvenir de Maxime Cornu’ with pure sulphur-yellow flowers.
‘La Lorraine’. – Flowers yellow, double.
‘L’espérance’. – Flowers 6 to 8 in. wide; petals pale yellow with a crimson stain at the base, arranged in two rows. F.C.C. 1931.
‘Mme Louis Henry’. – Flowers 6 to 7 in. wide; petals about thirteen, creamy yellow suffused with red. A.M. 1955.
‘Souvenir de Maxime Cornu’. – Flowers very fragrant, excessively double; petals yellow tinged brownish orange and red. The stems flop over under the weight of the flowers.
For culture, etc., see under P. suffruticosa. The flowering time is late May and early June.
P. lutea × P. delavayi – Hybrids of this parentage have been made deliberately in gardens and may also occur among seedlings where both species are grown. They (or at least the best of them) have flowers of a brighter red than in P. delavayi, and larger, but there is considerable variation. P. ‘Anne Rosse’ is the result of a deliberate cross between P. delavayi and P. lutea var. ludlowii, raised by The Earl of Rosse and given an Award of Merit when shown by him in 1961. The flowers are lemon yellow, 4 in. wide, with red streakings on the back of the petals.