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.
Broil the steaks at 500 degrees F until they are cooked to your desired doneness. For 1-inch sirloin steaks, this additional time is approximately 4 to 5 minutes for medium well and 2 to 3 minutes for medium.If you prefer your steaks rare, they may require no additional time in the oven beyond the initial searing time.ips. 1  Use a meat thermometer if you are unsure whether your sirloin steaks are done to your liking. 2  Steaks are medium-well at 150 to 160 degrees F and medium at 140 to 150 degrees F. 3  When cooking rare, you should not consume a steak less than 130 degrees since this may increase risks for food-borne illness.