persian lamb is the common western name for karakul (or Qaraqul) - a breed of sheep with the curly fleece.
newborn lamb fleece is usually very tight and curly and also usually black. it gets lighter and looser as the sheep age, but it's not uncommon for the fleece to be grey (shirazi) or even brown (kambar), just as might be in other breeds of sheep.

astrakhan, the closely-curled black or grey fleece of karakul lambs from the region around Astrakhan (a Tatar city and region in Russia, located on the Volga River, conquered by Ivan the Terrible in 1556)
also refers to the looped wool fabric made to mimic curly lamb
but i believe this is also the word used to describe the fleece of unborn or newborn lamb's fleece, which is very tight with small loops.


swakara is a trademark brand name for lamb fleece - curly karakul lamb being just one of them- raised in what is now called Namibia. the name is derived from South-West African Karakul = s-w-a-kara which is what the country was called from the 1960s through the 80s. some swakara fleece is loner haired or from more mature sheep that look totally different than the lambs.
(it's kind of like blackglama is a trademark name for black mink farmed in the USA - so the buyer knows where the fur came from) my grandmother had three of these coats with big "swakara" labels in them!

southwest africa is the old name for namibia, which is where a lot of these sheep were farmed by european colonists. prior to WWII it was called german sw africa, but after the war it was annexed and ruled by south africa until 1990 when apartheid ended and they took the name "republic of namibia"



broadtail is not a term i have heard before but i looked it up and found this great vintage site with all the hair-splitting terms
:
www.vintagefashionguild.org/cont.../121/