With more than 10,000 species, including magnolias, nutmeg, bay laurel, cinnamon, avocado, black pepper, tulip tree and many others, it is the third-largest group of angiosperms after the eudicots and monocots.

Some members of the subclass are among the earliest angiosperms and share anatomical similarities with gymnosperms like stamens that resemble the male cone scales of conifers and carpels found on the long flowering axis.

The circumscription is: Chloranthales Canellales Piperales Laurales Magnoliales monocots Ceratophyllales eudicots The clade includes most of the basal groups of the angiosperms.

In the original version of this system the circumscription was:[12] Both Dahlgren and Thorne classified the magnoliids (sensu APG) in superorder Magnolianae, rather than as a subclass.

[citation needed] Dahlgren divided his Magnolianae into ten orders, more than other systems of the time, and unlike Cronquist and Thorne, he did not include the Piperales.

[citation needed] Because of these difficulties and others, the synoptic table below imprecisely compares the definition of "magnoliid" groups in the systems of four authors.

The magnoliids is a large group of plants, with many species that are economically important as food, drugs, perfumes, timber, and as ornamentals, among many other uses.

[19] Some members of the magnoliids have served as important food additives, such as black pepper, nutmeg, bay laurel and cinnamon.

Likewise, some native peoples of the Amazon take a hallucinogenic snuff made from the dried and powdered fluid exuded from the bark of Virola trees.

[24] As with safrole, ingestion of nutmeg in quantities can lead to hallucinations, nausea, and vomiting, with symptoms lasting several days.

[25] A more severe reaction comes from poisoning by rodiasine and demethylrodiasine, the active ingredients in fruit extract from Chlorocardium venenosum.

In previous centuries, sailors would use Winter's Bark from the South American tree Drimys winteri to ward off the vitamin-deficiency of scurvy.

[19] Today, benzoyl is extracted from Lindera benzoin (common spicebush) for use as a food additive and skin medicine, due to its anti-bacterial and anti-fungal properties.

The tree Virola surinamensis (Brazilian "nutmeg") contains trimyristin, which is extracted in the form of a fat and used in soaps and candles, as well as in shortenings.