Integrative Biology 335:
Systematics of Plants

Unit IV. Rosids and Ericaceae

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Announcements:

Results of the first laboratory exam will be presented on the General Course Announcements web page, once they become available.

Our Pollination lecture (Wednesday, March 18th) will be presented by guest lecturer Dr. Ken Robertson of the Illinois Natural History Survey.

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Text and Other Resources:

You are responsible for pertinent material presented in Judd et al., Plant Systematics, A Phylogenetic Approach, 3rd edition (2008):

• Malvaceae: Judd et al. pp. 424–427
• Cucurbitaceae: Judd et al. pp. 396–399
• Brassicaceae: Judd et al. pp. 420–423
• Ericaceae: Judd et al. pp. 452–455
• Salicaceae: Judd et al. pp. 367–371
• Violaceae: Judd et al. pp. 364–367

Also, view Digital Flowers.

Below, illustrations are presented from Wendy Zomlefer's Guide to Flowering Plant Families by The University of North Carolina Press. In prior years, this was the required text for IB 335.

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Course Objectives:

After studying this material you should be able to:

1. Know the most important diagnostic features of these six families and be able to compare and contrast them. For more information on how to study families, refer to Objectives for Plant Families.

2. List the major clades to which these six families belong and describe their interrelationships.

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Plant Families Formerly Classified in Subclass Dilleniidae

Traditional classification system of flowering plants

In subclass Dilleniidae, Arthur Cronquist recognized 13 orders, 78 families, and 25,000 species. We will cover 6 of these families in this unit.

"The orders that make up the Dilleniidae evidently hang together as a natural group, but this group cannot be fully characterized morphologically. Like the Rosidae, the Dilleniidae are more advanced than the Magnoliidae in one or another respect, but less advanced than the Asteridae." (Cronquist, 1981)

Evidence from phylogenetic analyses of molecular data indicates that the Dilleniidae are not a monophyletic group (as is true for just about all of Cronquist's other subclasses of flowering plants).

"The groups that Cronquist called Rosidae and Dillenidae are largely intermingled, as had been suspected by anyone who had tried to teach according to Cronquist's system." (Judd et al., 2002)

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Classification and Phylogeny:

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EUDICOTS/Core Eudicots

ROSID CLADE

FABIDS (old Eurosids I clade)

Violaceae (Malpighiales)
Salicaceae (Malpighiales)
Cucurbitaceae (Cucurbitales)

MALVIDS (old Eurosids II clade)

Brassicaceae (Brassicales)
Malvaceae (Mavales)

ASTERID CLADE

Ericaceae (Ericales)

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There are some features in common among many members of this group. These are NOT synapomorphies for the group, however!

• The vast majority have a syncarpous gynoecium of two or more carpels
• When there are many stamens, they mature in a CENTRIFUGAL manner, i.e., from the inside out (versus centripetal, from the outside in)
• Parietal placentation is common
• Stamens usually not epipetalous
• Stamens often modified through fusion and elaboration
• Many have connate petals (sympetalous)
• Fruit is often a capsule or a berry
• Often woody plants

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Family Coverage:

Click on the family below to see your Class Notes with highlighted characteristics. Example pages indicate lists of species identified in your Class Notes.

Malvaceae (Mallow Family) Class Notes

• Examples of Family Malvaceae from Class Notes
• Schizocarp Maturation
• Zomlefer's illustration, p. 91
• Judd et al., Fig. 9.99, p. 427

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Cucurbitaceae (Cucumber Family) Class Notes

• Examples of Family Cucurbitaceae from Class Notes
• Zomlefer's illustration, p. 122
• Judd et al., Fig. 9.83, p. 399

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Brassicaceae or Cruciferae (Mustard Family) Class Notes

• Examples of Family Brassicaceae from Class Notes
• Tetradynamous stamens
• Silique vs. silicle examples
• Replum (false septum)
• Zomlefer's illustration, p. 126
• Judd et al., Fig. 9.96, p. 421

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Ericaceae (Heather Family) Class Notes

• Examples of Family Ericaceae from Class Notes
• Zomlefer's illustration 1, p. 78
• Zomlefer's illustration 2, p. 79
• Judd et al., Fig. 9.110, p. 453

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Salicaceae (Willow Family) Class Notes and Examples

• Salix, from Carroll E. Wood Jr., A Student's Atlas of Flowering Plants
• Salix staminate and carpellate flower illustrations

• Populus, from Carroll E. Wood Jr., A Student's Atlas of Flowering Plants
• Populus staminate and carpellate flower illustrations

• Zomlefer's family illustration, p. 115 in text
• Judd et al., Fig. 9.68, p. 370

• Salicaceae from Hawaii
• Salicaceae from the Virtual Field-Guide
• Salicaceae from Texas A&M

Test Review Question: Compare and contrast this family with the Betulaceae and Fagaceae. How are they similar? How are they different?

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Violaceae (Violet Family) Class Notes

• Zomlefer's illustration, p. 113 in text
• Judd et al., Fig. 9.66, p. 366

• Violaceae from U. of Hawaii
• Violaceae in Germany

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