There are a few defects you should be looking for on asparagus, but spreading tips is the most common you will find. The U.S. Grade Standards require that asparagus spears must be fairly compact. Spreading tips could be caused by over-maturity, as the spears were harvested just past their prime. The USDA classifies this defect as a condition defect, meaning the spears may have been harvested at the proper time, but as the asparagus is in storage the tips begin to spread.

The image above, courtesy of  U.C. Davis, shows a few spears with spreading.  You may occasionally find asparagus with spreading of this degree, as the spears pictured here would all be scored as serious damage.  The U.S. Grade Standards allow 10% of the spears to be damaged, including 5% with serious damage defects.

The USDA does supply some visual aids, unfortunately none of the images are in color, but you can still see the amount spreading that is allowed.  The image above is showing all the three spears being damaged by spreading.  Although the tips are only slightly spread, you can see the tips are beginning to flower, or go to seed.