Note: Family study exercises are designed
acquaint you with the major characters of some important flowering
families. Follow the guidelines on your instruction sheets. Answer
and diagram structures ON THE SHEETS and save them to study
Diagrams, in addition to those requested in the lab instructions, will
be useful. For exams, you will be expected to be able to identify
present in preserved or fresh floral material. Herbarium specimens will
be on display during each laboratory period. You should be able to
these to genus, family, and subclass by recognizing the characters we
For a copy of the overhead used in lab, click here.
This group of taxa, once called the "amentiferae"
(Englerian system), is characterized by floral adaptations associated
(wind-pollination). Thus, the flowers are small,
and often arranged in catkins.
EXAMINE catkins from Quercus, Carya, or Juglans,
but since floral dissections yields little information in this group,
focus your attention on the dried specimens that are set out. These
various taxa within the subclass.
Specimens marked with an orange dot are those for which you need to
know the subclass, family, and genus for lab practical. What
characters distinguish these taxa? Look at growth form and
features of pith, leaves, inflorescences, and fruit.
Betulaceae (birches)--Betula--catkins, exfoliating
bark, often serrate
Go on to the next
Fagaceae (oaks, beeches)--Quercus--often
Moraceae (mulberries, figs)--multiple fruits;
Morus--catkins; Ficus--fig; Maclura--Bois
Juglandaceae (hickories, pecans)--pinnately
compound leaves, fruit a nut; Juglans--chambered
with solid pith
Ulmaceae (elms, hackberries)--Ulmus--serrate
or double serrate leaves, perfect flowers, samaras,
twigs; Celtis with drupes and
Urticaceae (nettles -atypically herbaceous).--Urtica--stinging
SKETCH MEMBERS OF THESE FAMILIES:
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last updated 20 July 2007 MDR