Integrative Biology 335:
Systematics of Plants

Asterid Clade continued
Lamiaceae and Scrophulariaceae

Announcements:

Comments on your second lecture exam will be posted on the General Course Announcements webpage when grades become available.

Lecture quiz nine on plant dispersal mechanisms (fluorescent yellow sheet) is due in lecture Monday, April 13th.

Text and Other Resources:

You are responsible for the following pertinent material presented in your textbook (Judd et al., 2008, Plant Systematics: A Phylogenetic Approach):

Also, view Digital Flowers

Course Objectives:

After studying this material you should be able to:

  1. Know the most important diagnostic features of these two families and be able to compare and contrast them. For more information on how to study families, refer to Objectives for Plant Families. Diagnostic features are those distinguishing or identifying family features emphasized in lecture and lab (and treated in italics or boldface in your textbook).

  2. Know the major clade to which these two families belong (and why!).

  3. Construct a proper dichotomous key (in either indented or bracketed format) for the identification of the asterid families Ericaceae, Asclepiadaceae, Apiaceae, Solanaceae, Oleaceae, Scrophulariaceae, and Lamiaceae. This objective may be reached on an upcoming lecture quiz. If not, be prepared to do this on the final lecture exam.

Review of Angiosperm Classification

See p. 239 in your Class Notes, "Classification of IB 335 Plant Families." Review webpages for all families, be able to address all objectives listed, and read the required readings in your text. Also, see Table 9.1 in your text for an overview of angiosperm classification.

MAGNOLIIDS

MONOCOTS
EUDICOTS

Note: The one remaining family, Hamamelidaceae, is a core EUDICOT but is not assigned to any of the other eudicot clades. The classification above ignores the Fabid and Malvid subclades of the Rosid Clade, and the Lamiid and Campanulid subclades of the Asterid Clade. Other than the Caryophyllales, you do not need to remember the orders and subclades to which these families belong.

Another important note: You should also know the phylogenetic relationships among these major clades and be able to construct a simple cladogram to show these relationships. See Figs. 9.1, 9.2, 9.3 and 9.4 in your textbook.

Order Lamiales (Lamiaceae and Scrophulariaceae), Lamiids Clade

Remember, most members of the core Asterid Clade have sympetalous corollas and epipetalous stamens. These are synapomorphies for the clade! Those families that do not have these features will be mentioned in class. There are also other synapomophies and several general characterisitics outlined in our previous lecture.

The order Lamiales consists of about 22 families and 20,000 species. Many of these families have undergone considerable changes in classification (e.g., Scrophulariaceae). The order is undoubtedly monophyletic, being held together by the shared possession of a large suite of morphological, anatomical, chemical, and molecular characters (as described by Judd et al.).

Most members of the order have a two-lipped, bilaterally symmetrical flower forming a 2+3 pattern (i.e., bilabiate flower) and four epipetalous stamens arranged in a 2+2 pattern (i.e., didynamous stamens).

The Scrophulariaceae, as traditionally delimited, are polyphyletic, and is now divided into three major groups: Scrophulariaceae sensu stricto (s.s.), Plantaginaceae, and Orobanchaceae. In this class, we'll treat the Scrophulariaceae in their traditional sense (i.e., Scrophulariaceae sensu lato, s.l.).

The Oleaceae are also a member of this order. These plants have actinomorphic sympetalous flowers (usually of 4 petals) and only two epipetalous stamens.

Family Coverage:

Lamiaceae or Labiatae (Mint Family)


Digital Flowers

Lamiaceae Class Notes
Gynobasic style - a style that arises directly from the receptacle and appears to be inserted at the base of the ovary

Examples from Class Notes. Many species are economically important either for their essential oils (e.g., peppermint, spearmint) or use as spices (e.g., basil, rosemary, sage, savory, thyme, oregano).

Zomlefer text drawings (Fig. 120, p. 266)

Fig. 9.130 from Judd et al.

Lamiaceae are Polyphyletic. The traditional mints (traditional Lamiaceae) have arisen at least four times within the family Verbenaceae; therefore the mints are polyphyletic, arising within a paraphyletic Verbenaceae (fig. from W. Zomlefer text, Fig. 122). In this class, we'll focus only on those taxa traditionally placed in the family. The gynobasic-styled mints, with their four-nutlet fruits, comprise Clade 1 in this phylogeny. Approximately 90% of the Lamiaceae sensu stricto are represented by this single clade.

Scrophulariaceae (Figwort Family)


Digital Flowers

Scrophulariaceae Class Notes

Examples from Class Notes. Cardiac glycosides from Digitalis and many ornamentals.

Zomlefer text drawings (Fig. 114, p. 251)

Fig. 9.125 from Judd et al. (Plantaginaceae)

Phylogeny from Judd et al., Fig. 9.123, p. 475

In this class, we are covering the Scrophulariaceae in the traditional sense. However, as traditionally defined, the Scrophulariaceae is highly polyphyletic. Judd et al. place most traditional scrophs (e.g., Antirrhinum, snapdragons; Digitalis, foxgloves; Penstemon and Mimulus) in the Plantaginaceae (and call that the snapdragon family). They maintain Scrophularia (figwort) in the Scrophulariaceae. (The group that contains Scrophularia is given priority, according to the rules of nomenclature.) See the Judd et al. text for more information. A closely related family is the Orobanchaceae (broomrape family), a group of parasitic plants that lack chlorophyll.

The Legend of the Indian Paintbrush, a story by Tomie dePaola

Scrophulariaceae vs. Lamiaceae

Similarities:

Differences:

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