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.