Laboratory 6: Magnoliopsida, Subclass IV
|Objectives for this lab are to:
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.
- know the characteristics of the subclass Dilleniidae, if any
- learn key features of families and genera of the Dilleniidae
- be able to identify structures in preserved, fresh, or
mounted specimens of members of the Dilleniidae
- identify subclass, family, and genus for selected members
of the Dilleniidae
study exercises are designed to acquaint
you with the major characters of some important flowering plant
Follow the guidelines on your instruction sheets. Answer questions and
diagram structures ON THE SHEETS
and save them to study from.
in addition to those requested in the lab instructions, will be useful.
For exams, you will be expected to be able to identify structures
in preserved or fresh floral material. Herbarium specimens will be on
during each laboratory period. You should be able to identify these to
genus, family, and subclass by recognizing the characters we
For a copy of the overhead presented in lab, click here
1. Gossypium or Callirhoe
(winecup) Malvaceae - Malvales:
OBTAIN a flower and note the involucral bracts. The bracts in
this family often have a calyx-like appearance and are termed the EPICALYX.
The true calyx is synsepalous; the
corolla is PENTAMEROUS (5-parted) and actinomorphic. Remove
calyx and corolla. COMPARE what you see against fig. 16-13 (p.
330) in W&K and with the wall chart.
are _________________ i.e., the androecium forms a single unit that can
be easily removed from the gynoecium. Remove the androecium, observe
HYPOGYNOUS nature of the flower, and cross-section the
DIAGRAM your section,
pointing out placentation and carpel number:
FLORAL FORMULA ________________________________
KEY TO FAMILY (leaves not gland-dotted):
sp. (willow) - Salicaceae - Salicales:
OBTAIN staminate and pistillate inflorescences and examine
high magnification. NOTE that the staminate
flower is apetalous, is subtended by a single bract, and has small
the bract and filament (seeW&K fig. 16-16, p. 336 and the poster on
FLORAL FORMULA: ______________________
flowers of Salix are also
without a perianth. NOTE gland in the axil
of the pedicel. Glands in Salix produce nectar, i.e., insects
a pollination role in species of this genus.
REMOVE a single pistillate flower. NOTE BICARPELLATE,
SYNCARPOUS gynoecium with two styles. Under high magnification, tease
the ovary and note_________________ placentation and COMOSE
The COMA (tuft of hairs) will serve as a wind dispersal
for the mature seeds. This multi-ovulate ovary, which matures to form a
capsule, distinguishes the amentiferous Salicales from morphologically
similar taxa of the subclass Hamamelidae.
FLORAL FORMULA: ______________________
KEY TO FAMILY:
sp. (mustard) - Brassicaceae (Cruciferae) - Capparales:
OBTAIN a single flower. Examine and construct a floral formula
(tease open the ovary under high magnification and note lines of
to determine carpel number).
FLORAL FORMULA: _________________________________
DIAGRAM the gynoecium and androecium of this flower:
COMPARE your floral formula and diagram with p. 338 in W&K
and with the poster. What
is the term for this type of
stamen arrangement? ___________________
KEY TO FAMILY (leaves neither punctate nor bristly-glandular):
EXAMINE the key to genus for this family and note that
requires a specimen with
FRUIT. This is the case with many other angiosperm families, and is
one reason why a complete specimen is essential.
4. Gaylussacia or Vaccinium
sp. - Ericaceae - Ericales:
OBTAIN a flower and examine it.
CONSTRUCT a FLORAL FORMULA:
________________________________ Refer to fig. 16-18 b, c, d, l,
n (p. 340) in W&K.
SKETCH the corolla and androecium.
a. anther dehiscence: ___________________
b. placentation : _______________________
c. ovary position: ______________________
shape : ______________________
sativus (cucumber) - Cucurbitaceae - Violales:
OBTAIN a staminate
and a pistillate
flower. Develop a floral formula for each.
MALE FLORAL FORMULA ____________________
FEMALE FLORAL FORMULA _____________________
the ovary and count cells. DETERMINE the nature of
in the androecium.
LOCATE the nectary disk in each sex.
DRAW the male and female flowers of Cucumis:
What vegetative characters are associated with the Cucurbitaceae?