Purple Kush

The SR-71 cut is thought to be a very similar to Purple Urkle (possibly a hybrid) and has more of the typical "purple"/hashy grape flavor — it was passed most commonly by the SR-71 (now Blue Sky) Coffeeshop in the "Oaksterdam" section of Oakland, CA and may be Purple Afghani x Hindu Kush.  The Garberville Purple Kush is most notably held by Swerve of Cali Connection Seeds fame and tends to grow with some foxtails and has more of a straight-up Kush taste/smell with hints of the "purple".  Kyle Kushman's Las Vegas Purple Kush was claimed in a New Yorker article to be a special Purple Indica x Northern Lights find, but many have since claimed it's an S1 Bubba Kush of some kind due to the dark flavors present.  And finally, many old-school people claim that none of the famous clone-only PK's around are in fact the original Purple Kush, which is said to be a very special Purple Pakistani variety that was found in the late 70's or early 80's.  As you can see, the history of a strain that's been renamed several times and has several legit versions floating around gets very murky quickly.

Purple Afghani x Hindu Kush (one version — see description for more info)

See above.  The SR-71 cut was originally named "Ultraviolet" by its original grower in Oakland, CA (credited as "K" from Trichome Technologies according to SR71's catalog).

Pungent, with notes of "purple" (incense, perfume, musky grapes), and the spicy Kush end of the spectrum as well.  The SR-71 and Garberville cuts are more "purple" in both flavor and smell compared to the Kyle Kushman/Las Vegas Purple Kush.

Much like the smell, the flavor is a dark fruity musk with a bit of sweetness at times — a great blend of the typical purple flavor and traditional Afghani/Pakistani Kush varieties.

Eminently relaxing and rather potent, Purple Kush is definitely in touch with its Afghani-Pakistani roots.  Coming on with a slight rush of energy, that subsides quickly and leaves the user with a floaty, highly medicated body experience that makes aches and pains as well as anxiety/stress melt away.  Purple Kush is also known for being a long-laster, normally going out to the 3 hour mark.  Recommended highly for body pain, muscle relaxation, mood elevation, appetite stimulation, and sleep aid at higher dosages.

Grows well in soil or hydro — they all have fairly strong yield considering the possible Urkle lineage and traditionally slow vegetative growth of purple strains.  Cooler temperatures at night and a longer flowering time will help to bring out the purple coloration to a higher degree.