OK, looks to me like casing damage from a hard impact. Stone maybe? Probably an impact that a quality tire would probably (but not always) brush off but that caused the threads of a layer of cord to break. (The cord on nearly all tires runs diagonally in both directions. Break one layer and the entire body of the tire skews diagonally. A partial slice from a sharp piece of metal can do the same thing, only from the other side and the warp-age would be a mirror image. Either way, you have roughly 1/2 the original strength.)
So, best to call this tire dead. It would probably get you that 100 miles home but it you are posting from home, start your next ride on a new one. I don't recognize your tire but a good one to consider in the mid price range is the Panasonic Pasela, available in a wide range of widths and in both 700c and 27". The Paselas don't like sidewall abrasion at all so mind my cautions of my first post but the cord is supple and strong and tolerates impacts very well.