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.
Warm sirloins will remain more tender and juicy during the grilling process than sirloins steaks that are put on the grill cold. Preheat the grill to medium-high or 400 degrees Fahrenheit. Rub the steaks with seasoning, if you are using any, and grill the steaks for four to five minutes on each side. When they are finished, the steaks should register 135 degrees Fahrenheit on an instant-read thermometer for medium-rare.