Arecidae, Zingiberidae, and Liliidae

Objectives for this lab are to:

know the characteristics fo the subclasses Arecidae, Zingiberidae, and Liliidae
learn key features of families and genera within the Arecidae, Zingiberidae, and Liliidae
be able to identify structures in preserved, fresh, or mounted material of plants from these subclasses
identify subclass, family, and genus for selected members of these subclasses.

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.

1. Arisaema--Araceae (Jack-in-the-pulpit) - Arales:

Work in pairs or look at the demo. OBTAIN an inflorescence and compare with W&K p. 414 and lecture notes. Note SPATHE, SPADIX, and highly reduced flowers. Species of this genus are monoecious or dioecious; male flowers are composed of a cluster of nearly sessile 2- to 4-celled anthers opening by terminal slits or pores; female flowers consist of a 1-celled ovary with a broad stigma and up to 6 ovules. Some of this preserved material has staminate flowers and some of it has pistillate flowers. (A few odd ones have both!)

OBSERVE and DRAW both types of flower.
EXAMINE the key to monocot families and note that it would be difficult to identify this family if you were not aware of this specialized and characteristic inflorescence.

2. Lemna or Spirodela - Lemnaceae - Arales

Members of this family are stemless, leafless, floating aquatics with a thalloid body and extremely reduced flowers. Reproduction is usually by budding. Species of Wolffia, at about 1 mm long, are the world's smallest flowering plants! Examine and SKETCH the demonstration material.

SUBCLASS X - ZINGIBERIDAE

1. Bromeliaceae - Bromeliales

Examine material on display representing this family. Note epiphytic habit, scurfy leaves, and colored bracts and flowers, and other characteristics discussed by W&K on pp. 416-417.

KEY the family in reverse. That is, start with the family and go through the key until you reach couplet number 1. What characters does the key use to key out the Bromeliaceae?

What is the Bromeliad genus found locally? ______________________ One species grows in balls, the other in long festoons. It is hard to believe these plants are in the same family as pineapples!

SKETCH the samples provided.

3. SUBCLASS XI - LILIIDAE

1. Liliaceae and Amaryllidaceae - Liliales:

EXAMINE Unknown "A".
CONSTRUCT a floral formula for this particular plant: ____________________________________
KEY to family (leaves grass-like) _______________________________________
KEY this plant to genus (neither A nor B has an onion smell) _______________________________________
Now consider Unknown "B" (click for a similar plant).
EXAMINE the floral material carefully. CONSTRUCT a floral formula for your specimen ____________________________
KEY to family________________________________________________________________
How does this specimen compare with sample A in regard to ovary position? ____________________________________________________
NOTE that your lab key and W&K (p. 419) place both of these plants in the same family. Previously, these plants were split into the Liliaceae and Amaryllidaceae. Currently, some authorities divide the Liliales into many segregate families.

Examine demonstration material of the Agavaceae, if there is some. What characters distinguish this closely-related family?

DRAW your samples :

2. Orchidaceae -Orchidales

OBTAIN an orchid flower. NOTE the highly modified floral structure, especially the COLUMN, derived from fused stamens, style, and stigma. What is the ovary position? ____________________. Refer to the diagrams on page 426 of W&K and the poster on the board as you dissect your flower.
What is a pollinium?________________________________
Where have we encountered pollinia before?______________________________
SKETCH the flower and column of the orchid:

OBSERVE the demonstration material. This may include specimens of Spiranthes (ladies' tresses), Dendrobium, Paphiopedilum, Pogonia (rose pogonia) or others. Hundreds of species of orchids are grown for their flowers. Vanilla planifolia is the source of vanilla flavoring.

last updated 24 July 2007 by MDR

Laboratory 10: Liliopsida II, Subclasses IX, X, and XI