All Hybrid teas (now) as far as I know are equal Tetraploids. This means they have four sets of chromosomes split equally between the seed and pollen (this will be important later). When a bloom is produced for reproduction the seed carries two sets of chromosomes and the pollen has two sets of chromosomes. The original " Teas" or China teas are Diploids or having two sets of chromosomes. So the seed and pollen each have one set of chromosomes.

Hybrid Teas are a cross between Hybrid perpetual (also tetraploids) and teas (diploids). The resulting offspring were Triploids, three sets of chromosomes (La France) and to a greater or lesser degree sterile, as they couldn't divide three sets of chromosomes evenly in half to reproduce. Tea roses obviously did reproduce. They did it by either a seedlings taking more of the genetic material than they were supposed to and being born tetraploids (Lady Mary Fitzwilliams). ["La France" is generally recognized as the first Hybrid Tea, though according to Brent C. Dickerson it was released as a Bourbon hybrid in 1867. Mr. Dickerson says that it is more appropriate that the first hybrid teas would be in 1872. They were 'Cheshunt Hybrid' and 'Mme. Lacharme'.  I feel this is a play on words as Guillot had to convince the rose community that "La France" was something different and was a " Hybrid Tea" (which at the time wasn't a class of rose) rather than a "Hybrid Damask".  He couldn't very well release a rose in a class that didn't exist.

Breeders produced conversions from triploid to tetraploid intentionally by placing known good pollen on a hopeful seed or hopeful pollen on known good seed. The rose themselves, by self-pollination, making a conversion and either a seed or a grain of pollen (pollen had a much better chance of conversion as it is produced in vast greater quantities) did not split evenly and carried two sets of chromosomes. Therefore producing a tetraploids or biploid offspring. I believe Herr Kordes produced his Kordisii Hybrids by letting "Max Gaf" self, though it being a sterile Triploid converted to a fertile tetraploid (I think), so he wouldn't know the pollen parent for sure.

Now I am not saying hybrid Perpetual and Tea are the only genes swimming around in you tea roses. First of all Hybrid Perpetuals were themselves a mixed bag as I described in the Hybrid Perpetual section. Teas like Hybrid perpetuals are vast melting pots and carry the genes from many different species of rose. Breeders were and still are looking for something new so they stick in something to make their rose different than what is already on the market. Queen Elizabeth for instance is a cross of " Charlotte Armstrong" X "Floradora" "Floradora" is a cross of Baby Chateau (a cross of "Aroma" X "Eva" "Eva being a Hybrid Musk) and R. roxburghii a species. Now for my personal opinion on Hybrid Teas: I truly like them and they have a place in any garden. I do feel they are very formal and rather puny and they lack the simple charm of the old garden roses. I also find that my olfactory lobes feel very left out when I do as everyone I know does when they see a beautiful rose. I take a whiff. I do like teas, however very few roses can equal the visual display of the perfect symmetry, play on subtle color and petal substance as "Peace" (Though I believe that the mass breeding of "Peace" was the start of Fragrant-less roses) or the kaleidoscope color changes, beautiful healthy foliage and sweet fruity fragrance and ruffled petals of "Rio Samba".

Basic care: The biggest mistake I see people making is to try to grow Teas in too little light. This is like putting a gold fish in a mud puddle and expecting it to become a large beautiful fish. A tea rose grown in insufficient light will last a little while, but your rose will bloom less and less putting out more and more foliage trying to compensate for the lack of light. Then one spring (one or two not five) your rose doesn’t come up. It starved to death because it couldn’t store enough nutrients though out the growing months to get through the winter. Give your roses at least six full hours of direct sunlight. Fertilize from spring as soon as you see the first signs of life and continue (follow label directions) till late summer so the roses have time to go into dormancy naturally. I know a lot of people have problems with using sprays but I use insect and fungicide sprays to control black spot and insects. I am careful and spray only my roses . If you live in a place that has cold winters like I do here in Illinois plant your roses a couple of inches above the graft union. This will not only prevent the union from freezing but will also encourage your rose to produce it's own roots. I have split my Rio Samba twice because it grew so large on its own roots I have had Rio for around 10 years too. I have pictures of my Teas posted.