Laboratory 8: Magnoliopsida, Subclass 6

Asteridae

Objectives:
  • know the characteristics of the subclass Asteridae
  • learn key features of families and genera of the Asteridae
  • be able to distinguish the three head types in the Asteraceae
  • be able to identify structures in preserved, fresh, and mounted specimens of members of the Asteridae
  • identify subclass, family, and genus for selected members of this subclass
Safety concerns for this lab:  Use caution with dissecting tools, wear protective eyewear if working with specimens preserved in Carosafe, dispose of Carosafe specimens in proper waste container.

Note: Family study exercises are designed to acquaint you with the major characters of some important flowering plant families. Follow the guidelines on your instruction sheets. Answer questions and diagram structures ON THE SHEETS and save them to study from. Diagrams, in addition to those requested in the lab instructions, will be useful. For exams, you will be expected to be able to identify structures present in preserved or fresh floral material. Herbarium specimens will be on display during each laboratory period. You should be able to identify these to genus, family, and subclass by recognizing the characters we discuss.   For a copy of the overhead presented in lab, click here

The Asteridae is the last and most derived dicot subclass. The following unifying characters apply to about 80% of the species, and most species will have at least 2 or 3 of these: corolla fused, stamens epipetalous, stamens as many as or  fewer than the corolla lobes, ovary bicarpellate.

1. Asclepias - Asclepiadaceae - Gentianales:

2. Physostegia or Stachys - Lamiaceae (Labiatae) - Lamiales:

3. Asteraceae (Compositae) - Asterales:

Additional Families

There are many other important families in the Asteridae. Have a look at a few of them: