Albiflora X Macrophylla
P. macrophylla ("big leaf") is one of lour or five species that grows wild in the Caucasus mountains. This rather dwarf plant has small cup-shaped white flowers with a strong odor of cloves [or is it nutmeg?] and its leaves are the largest, coarsest, and glossiest in the entire peony kingdom. A single leaflet often measures nine by six incheshuge for a peony. These give off a strong smell of English box in the spring sunlight.
All the Caucasus species are extremely early, macrophylla vying with tenuifolia each spring as to which shall be the first to bloom; usually between May 10 and 15 in the Clinton latitude. It imparts to its hybrid children a strong tendency to earliness. By this one cross alone, the peony blooming season was extended by two or even three weeks.
Starting in about 1918, more than a thousand plants of this cross were produced, including the second, third, and even fourth generation, plus several lateral relatives. The vast majority are white; there are a few with pale blush tinge. All are single except as otherwise noted. This cross takes fairly well: over the random period 1926-31 it was made one hundred and forty-three times, and yielded four hundred and forty-four seeds, an average of 3.1 seeds per cross.
Not too bad! One of the first hybrids to appear has ever since remained near the head of the list: the immense shimmering white single. Chalice. In 1925 it was noted as a "corker" and is still widely so considered. Another almost as lovely is Seraphim.
Most first-generation hybrid peonies are sterile, at least during the earlier years of their growth. Some remain so permanently. Others, however, after the plants have attained to full maturity, may begin to set an occasional seed, though never very many, and these seeds produce plants which are of course the second generation from the original crossF2 plants as the botanist calls them. In these F2's a surprising and a welcome change occurs, for the natural fertility is in large part restored. So it is with the macrophylla hybrids: the F2's have strongly viable pollen and are regular and abundant seed-setters.
Among these F2's are Serenade. Archangel, May Lilac, and the heavy seed-setter No. 4992.
Then there are the "back-crosses" in which pollen from one of the hybrids was placed back onto an albiflora variety. This gave Garden Peace and Requiem.
Professor Saunders recommended to (50:) the hybridist who might be trying to get double hybrids to make use of the Chinese peonies James Kelway and Lady Alexandra Duff, as he had had several examples of their tendency to throw doubleness into their hybrid offspring.
Professor Saunders early noted that a cross usually gives different results when made in reverse. It was found that when a flower of macrophylla was crossed by pollen from an albiflora [presumably imported from the South in late May] there was a strong tendency to doubleness. And another difference appears: the cross in this direction takes very badly: "1929: 27 crosses, 14 seeds; average .5 seeds per cross."
Triple Hybrids: Officinalis X ("Albi" X "Macro" F2)
Stemming from this cross are two fine triple hybrids. One of the white "Albi" "Macro" F2's crossed with officinalis Rosea Plena gave Pageant, a spectacular tall rose pink with a 4-inch shock of golden petalodes. Crossed with Otto Froebel, it gave Mid May, a vigorous
plant with blush flowers.