At the end of the Georgian period and beginning of the Regency, there were all sorts of wonderful developments and explorations going on. One of the crucial turning points in the history of roses was the introduction of the roses from the Orient. These were key to the development of truly remontant--or reblooming varieties. Without the Oriental roses, our modern roses would not exist. And there probably wouldn't be any yellow roses either!
One thing to note: There were no yellow roses (as we know them) were grown during the Regency period. There were a few species (single, 5 petal flowers) in the Burnet class and some others I mention below, but I suspect none of you, if you saw them, would say they were roses. There were some yellow roses in Persia, but they could not survive the colder European weather and were not grown in England until well after the Regency.
Up until the introduction of China Roses, the colors of roses were mostly shades of pink, white (esp. in the Alba class) with a few deep pink or purple (mostly in the Gallica class). That's pretty much it. When you hear of the red rose in the 'War of the Roses' what is meant is a rather deep pink or purplish color. It took the introduction of the China rose to obtain the first clear crimson.
The Japanese or Rugosa Roses were recorded in Europe by Thunberg in 1784, and it reached England from Japan. They were first introduced by Lee and Kennedy of Hammersmith in 1796 as a novelty. Unfortunately, it was not popular. You can see what this class of rose looks like at: http://www.amypadgett.com/scabrosa.htm (this is a later specimen of this class of rose, but looks very similar.)
The Chine Rose, on the other hand, was pretty much the crucial rose in the development of our modern roses.
The scientific name, Rosa chinensis, was given to this class of rose in 1768 in Gronovius's Herbarium. This rose was red. The roses we are most interested in are really four roses, documented by Dr. Hurst as the four stud Chinas. They were:
The 'Slater's Crimson China' was a double rose and the first true red, or crimson.
Parson's Pink China
Slater's Crimson China
The Chinese worked intensively with roses for nearly 1000 years to produce the China and Tea-Scented roses which were perpetual-blooming, or remontant. The colors they achieved included pink, true crimson, salmon, and pale yellow. These roses not only bloomed all summer, but had an entirely different shape than the European roses, as well as a different texture, a dwarf habit, and entirely different leaves and twigs than the European varieties.
China Roses are small to medium sized shrubs with smooth wood that is reddish when immature. It has sparse, small, red prickles. The leaves tend to be sparse as well and have 3-5 pointed segments. The leaves are smooth and tend to be reddish when they are young. The flowers, if they are singles, have 5 petals, or twice that many if double. The petals are very silky and tend to be a little "limp" after opening. (You might want to look at the pictures of 'Slater's Crimson China' at http://www.amypadgett.com/slaters_crimson_china.htm and 'Old Blush' is identical to 'Parson's Pink China' which you can see at: http://www.amypadgett.com/OldBlush.htm )
The Tea Rose or Tea-Scented Rose class was also important, but less so in England, where it had difficulties surviving the weather. It is definitely a warm-weather rose (and does very well in North Carolina gardens, e.g. http://www.amypadgett.com/MarieVanHoutte.htm ).
'Fortune's Double Yellow' or Rosa odorata pseudindica or 'Beauty of Glazenwood' or even 'Gold of Ophir' (roses have lots of names, sometimes...) is a Tea. It was introduced by Robert Fortune in 1845. He brought it from China and at the rose, it was the most brilliant rose existing.
It had the same problems that all Tea Roses do in England--not a strong grower and difficulties surviving the winter. It had semi-double flowers that are loosely constructed and are a bright yellow with a flush of coppery-scarlet. They are borne singly or in small clusters during the summer.
It is interesting to note that initially, growers did not understand how to deal with Tea Roses and they routinely cut away all the flowering wood. Tea Roses and most China Roses bloom upon what are essentially "twigs", which is what growers often cut away. In any event, it took a while for growers to realize this and allow the plants to flower without pruning, except right after flowering.
Another important Tea Rose is Rosa odorata ochroleuca or 'Park's Yellow Tea-Scented China', brought to Europe in 1824. This rose, in 1830, helped in the development of the pale yellow and near-yellow Noisettes, beginning with the rose 'Lamarque'.
These two roses, 'Park's Yellow Tea-Scented China' and 'Fortune's Double Yellow' brought the valuable yellow coloring into many of our Hybrid Teas of today.
The other yellow rose of note is 'Persiana' or 'The Persian Yellow Rose' which came to England in 1838, brought by Sir Henry Willock. For a while, this was the most brilliant double yellow rose available in English gardens. The "Gardeners' Chronicle" in 1843 advertised this rose for the expensive sum of 15 shillings. This was the first really popular yellow rose, despite the cost.
On a sad note, it is another yellow rose, Rosa foetida and the variety Rosa foetida 'Persiana' which also brought with them into our roses, the disease blackspot. Although these roses are yellow, they were difficult to grow and smelled like rotting carrion, so....the only saving grace was that they were yellow. They were difficult to grow in England.
There was also Rosa Lutea punicea or 'Austrian Copper Brier', and 'Bicolor' which were yellow on one the reverse side and copper on the upper side, but although they were available after 1815, they were not particularly attractive, had blackspot, and were not generally grown. They also did not look like roses you would recognize and did not smell at all nice.
"The Old Rose Advisor" by Brent C. Dickerson
"Modern Roses XI, The World Encyclopedia of Roses" from Academic Press
"The Graham Stuart Thomas Rose Book" by Graham Stuart Thomas"
"The Quest for the Rose" by Roger Phillips and Martyn Rix
"Old Roses and English Roses" by David Austin
"100 Old Roses for the American Garden" by Clair G. Martin
"Botanica's Roses" by William A. Grant
"The English Roses" by David Austin
And several "Gardener's Dictionaries" from 1800.