Lab Work 1 EXTERNAL MORPHOLOGY
Table 1. Variations in flowers and floral parts
SCIENTIFIC REGULAR/ COMPLETE/
CALYX COROLLA STAMEN PISTIL
NAME IRREGULAR INCOMPLETE
Gladiolus sp.
Irregular Incomplete Tubular Lip Present Absent
(Sword lily)
Clivia
miniata Regular Complete Distinct Funnel form Present Present
(Bush lily)
Foeniculum
vulgare Irregular Incomplete Distinct Apetalous Present Absent
(Fennel)
Tithonia
diversifolia Regular Complete Tubular Polypetalous Present Present
( Marigold )
Phaseolus
vulgaris Irregular Incomplete Tubular Papilionaceous Absent Present
(Sitaw)
Pisum
Irregular Incomplete Distinct Papilionaceous Present Absent
sativum (Pea)
Anthurium
Polysepalo
andraeanum Irregular Incomplete Apetalous Present Absent
us
Hibiscus
rosa-sinensis Regular Complete Distinct Salvershape Present Present
(Gumamela)
Zantedeschia
aethiopica Irregular Incomplete Tubular Apetalous Present Absent
( Arum-lily )
Euphorbia
Polysepalo
pulcherrima Irregular Incomplete Apetalous Absent Present
us
(Poinsettia)
Rosa sp.
Regular Complete Distinct Campanulate Present Present
(Rose)
Paspalum
(Crown Irregular Incomplete Pappus Apetalous Absent Absent
grass)
Cattleya Irregular Incomplete Tubular Lip Absent Absent
Hydrangea
macrophylla Polysepalo
Regular Incomplete Gamopetalous Present Absent
(Big leaf us
hydrangea)
Callistemon
citrinus
Irregular Incomplete Pappus Bilabiate Present Absent
(Crimson
bottlebrush)
Daucus
carota Irregular Incomplete Distinct Apetalous Present Absent
(Carrot)
Althea rosa
Irregular Incomplete Scabrous Campanulate Absent Present
(Hollyhock)
Gerbera Polysepalo
Regular Complete Polypetalous Present Present
jamesonii us
(Daisy) sub
for Dahlia
Tridax
procumbens
Polysepalo
(Coatbuttons Regular Complete Polypetalous Present Present
us
or Tridax
daisy )
Cosmos
caudatus Regular Complete Distinct Gamopetalous Present Present
(Cosmos)
Table 2. Types of inflorescence
VARIATION
VARIATION ACCORDING TO
TYPE OF
SCIENTIFIC NAME ACCORDING TO THE
INFLORESCENCE
LOCATION ARRANGEMENT
OF FLOWERS
Gladiolus sp.
Indeterminate Axillary Spike
(Sword lily)
Clivia miniata
Determinate Fascicle Umbel
(Bush lily)
Foeniculum vulgare
Determinate Terminal Cymose
(Fennel)
Tithonia diversifolia
Indeterminate Fascicle Head
( Marigold )
Phaseolus vulgaris
Indeterminate Fascicle Raceme
(Sitaw)
Pisum sativum
Determinate Terminal Solitary terminal
(Pea)
Anthurium
Determinate Radical Spadix
andraeanum
Hibiscus rosa-sinensis
Determinate Extra-axillary Solitary axillary
(Gumamela)
Zantedeschia
aethiopica Indeterminate Radical Spadix
(Arum lily)
Euphorbia pulcherrima
Determinate Terminal Cyathium
(Poinsettia)
Rosa sp.
Determinate Terminal Solitary terminal
(Rose)
Paspalum
Indeterminate Spike
(Crown grass)
Cattleya orchids Indeterminate Terminal Racene
Hydrangea
macrophylla Indeterminate Terminal Corymb
(Big leaf hydrangea)
Callistemon citrinus
Determinate Extra- axillary Raceme
(Crimson bottlebrush)
Daucus carota
Indeterminate Fascicle Compound umbel
(Carrot)
Althea rosa Determinate Terminal Cyme
(Hollyhock)
Gerbera jamesonii
Indeterminate Terminal Head
(Daisy) sub for Daisy
Tridax procumbens
(Coatbuttons or Tridax Determinate Terminal Single
daisy )
Cosmos caudatus
Indeterminate Terminal Head
(Cosmos)
ANSWERS TO QUESTIONS
1. Why do flowers develop into clusters? Is there any taxonomic significance?
Souer, E.et al, (1998, February 15) defines an inflorescence is a group or cluster of flowers
arranged on a stem that is composed of a main branch or a complicated arrangement of branches. It is
also the modified part of the shoot of seed plants where flowers are formed. Inflorescence in some
flowers are brought about by the shift from the vegetative to reproductive phase of a flower involving
the development of an inflorescence meristem that generates floral meristems. This depends on which
meristems become flowers and which become shoots.
2. What advantage(s) if any, do flower clusters have over that of single flowers?
Flowers in clusters or termed as inflorescences are complex structures with many functions
which makes it advantageous than that of a single flower. It helps in the transfer of pollen and
optimization of the plant's reproductive success. During flower and fruit development they provide
nutrients to the developing flowers and fruits. At fruit maturity they support the fruits prior to
dispersal, and facilitate effective fruit and seed dispersal. From a structural point of view,
inflorescences have played important roles in systematic and phylogenetic studies. As functional units
they facilitate reproduction, and are largely shaped by natural selection. (Kirchoff, B. K., & Claßen-
Bockhoff, R.,2013)
3. Why do you think Linnaeus considered flower as the most reliable basis of plant
identification?
Linnaeus considered the flower as the most reliable basis of plant identification since it has
great variation which can be described in a systematic way to identify and distinguish species. Other
parts of a plant, specifically the vegetative aspect may have alterations due to climatic conditions,
geographical location, and various biotic and abiotic stresses. In these cases, the floral parts or the
floral formula can play a very important role in the correct identification of the species.
REFERENCES
Kirchoff, B. K., & Claßen-Bockhoff, R. (2013). Inflorescences: concepts, function, development and
evolution. Annals of botany, 112(8), 1471-6.
Souer, E.et al, (1998, February 15). Genetic control of branching pattern and floral identity during
Petunia inflorescence development. Retrieved February 27, 2019, from
http://dev.biologists.org/content/125/4/733
