Pipe Tobacco: All pipe tobaccos are either a blend of different types of tobacco (90%) or, and there a few of these, one type of tobacco that has been treated or processed in some way. The only straight, single type, tobaccos that I am aware off are Virginias. E.G. Gawith's Full Virginia Flake.
FLAKE: Tobacco that has been pressed into a brick then cut into flat flakes that may vary in size. It must be rubbedout into smaller pieces before smoking. Generally flake tobaccos are cool burning and with a few exceptions ( Gawith Balkan Flake, Krumble Kake), are pure Virginia's.
RIBBON CUT: Tobacco that has been pressed then cut into long, thin ribbons. It is not as long or as fine as SHAG cut. Shag cut is very similar to cigarette tobacco in cut. This can be Virginia or Oriental.
CUBE CUT: Tobacco that has forced through a sieve, grate or chopped into small pieces that are often square. Typically, cube cuts are Burley tobacco.
Curly - this is tobacco leaf spun into rope and sliced. It typically is very slow burning hence it is cool smoking.
SHAG: Tobacco which has been very finely long cut. In Edwardian times it was considered an poor quality tobacco. Today, it is not. An example is McClellands Shag Cuts, Baker Street, 221 , etc. Most shags have a high proportion of Virginia in them as Virginia tobaccos have long leaves that allow this cut.
NAVY CUT: Originally the tobacco was favored by sailors. They would put it in a long thin canvas tube and twist it tight. When taken out it was a thick rope of tobacco that they could carry in their pocket. They could cut off a plug to chew or slice it to smoke in a pipe. Escudo, Three Nuns Slices and Bengal Slices are types of sliced plug. Normally it is a slow burning tobacco fitting with its sailing origins. Navy blends are often steeped in Rum as this what sailors used to to do.
The tobacco plant is unique in that the plant develops different characteristics and flavors contingent on the type of soil and climate it is grown in. Many tobaccos blends have added natural and artificial flavorings added, but if the climate and soil is of poor quality the tobacco will never be a quality smoke. That is why tobacco isn't grown in the UK. Good soil but too wet a climate.
VIRGINIA - comes in an almost infinite variety red, brown, black, lemon, orange, wheat orange-red etc.
It is the mildest of all blending tobaccos but because it has the highest natural sugar content by itself it can often burn hot.
It is used in almost all blends as it burns well.
Its characteristic is a natural sweetness but certain types have to steamed or stoved to eliminate their tannic acids which can impart an acidic taste.
BRIGHT Virginia - is from the Carolinas and is normally very pale in color almost white.
BURLEY - "white burley" - is a mutation of Virginia that developed in Maryland after the Civil War. It has natural tobacco taste, almost nutty, and will never "bite." It takes flavorings and casing especially well as it has very little taste of its own. It is the most common base tobacco in drugstore blends.
CAVENDISH - Cavendish is a process of curing and/or a method of cutting tobacco leaf. A steamed Virginia is a Cavendish. Cavendish takes aromatics very well. "Black Cavendish, is Kentucky Green River Burley steamed with either sucrose or fructose and not washed," Craig Tarler of Cornell & Diehl. The best Cavendish is washed out after steaming to remove the sweetness. The treating and/or the cut bring out a natural sweet taste that is typical of Virginia tobacco. Cavendish is a tobacco that has a light taste, is mild and packs easy.
All Virginia tobaccos have a high nicotine content because they typically are grown in nitrogen rich soils.
Condiment tobaccos: These have a very strong taste and often aroma. They are rarely smoked straight. They normally used as flavoring in blends and to modify the burning characteristics of a blend.
Perique - Louisiana - is grown in only in St, James Parish in Louisiana. It originated with Native Americans who steeped the tobacco in its own juice in hollow logs. Today, its produced by fermenting twist in their own juices under pressure for 9-10 months. It is still steeped in its own juice to make it Perique. It is very strong and few blends have more than 10-15% added.
Havana - Is grown in the Vuelta Region of Cuba - in Santiago Province. The best cigars in the world come from there.
Deer tongue -is the leaf of the wild vanilla plant. It is very hot if over used. It is added in small quantities to blends and has a unique aroma.
Oriental tobaccos: They are typically very fragrant, variable sugar content and have virtually no nicotine because they are grown in nitrogen poor soils in arid regions of the Middle East and Greece, Bulgaria and the former Yugoslavia. They are bought up in massive quantities by the large cigarette companies.
There are two broad types of oriental Turkish and Greek.
The Greek includes Basma, (Frog Morton on the Town), Mahalla, Xanthi, (Ashton Old Dog), Dubek, Yenidji (original Balkan Sobraine).
The most common Turkish type is Smyrna, the best of which is called little ears in Turkish.
Latakia - From Syria/Cyprus (smoked Oriental tobacco). It was accidentally "discovered" after a bumper crop in the 1880's. The surplus tobacco was stored in the rafters of Arab farmhouses. Arab peasant farmers, "fellahin" used wood and when short of wood camel dung for cooking and heating in the winter. The smoke cured tobacco imparted a unique flavoring and taste that was discovered when it was smoked.
Cyprian latakia is smoked over a banked fire of mountain shrubs, pins trees myrtle and other native woods in sheds.
Syrian latakia is smoked over different woods and herbs. The main one is Syrian oak. Syrian latakia is normally lighter in color and smokier to taste than Cyprian.
Drama - Macedonia - Greece - is a strong condiment tobacco. It is used very sparingly in blends.
One of the characteristics of Latakia and other Oriental tobaccos is that they are grown in nitrogen poor soils. This means a low sugar and nicotine content but makes the tobaccos naturally spicy.
Sources: The above information has been culled from a variety of sources including but not limited to: Articles by William Serad, e-articles by G.L.Pease. talks with Craig Tarler, William Ashton Taylor, ( he was trained as a blender by Dunhills), Charlie Price, my own travels in Eastern Turkey, Cyprus and Syria, and assorted other arcane sources.