The predominant function of thorns, spines and prickles is deterring herbivory in a mechanical form. Not all functions of spines or glochids are limited to defence from physical attacks by herbivores and other animals.echnically speaking, many plants commonly thought of as having thorns or spines actually have prickles. Roses, for instance, have prickles. Other structures that look alike are spinose teeth, spinose apical process, stiff trichomes and stinging trichomes.
1 This will help the sirloin cook from all angles and sear in the juices.  Grill the steak with lid down for 4-5 minutes depending on thickness. When grilling steaks, you need to resist the urge to open the lid and look.
Take a basting brush and spread extra virgin olive oil on both sides of the steaks. This will impart a great flavor on the meat and serve as a anti-cticking agent. If it's good quality sirloin, then all you need to add is some sea salt and fesh ground pepper on both sides of the steak. If you are looking for additional flavor then you can put the sirloins in a ziploc baggie with your favorite BBQ sauce for about 30 minutes prior to grilling. And never cook a steak past medium.