Flowers PDF

“Flowers”

reproductive shoot composed of whorls reproductive w horls of modified leaves inserted in a modified stem (peduncle)

Floral Parts A flower contains four sets of parts arranged in whorls on the receptacle the swollen tip of the peduncle Accessory parts 1. Sepal (calyx) (cal yx) - protec protects ts the the inner inner part part of of flower - preve prevents nts dessica dessication tion 2. petal (corolla) - most most noticea noticeable ble port portion ion - diffe differe rent nt colo colors rs Perianth – calyx and corolla

Essential Parts: 1. Stamen (androecium) - male game gametophy tophyte te a. pollen containing chamber (microsporangium) b. anther c. filament 2. Carpel (gynoecium) - female female re reprodu productive ctive leaf and ovule bearing structure of a flower a. ovary - swollen basal part b. stigma c. style (tube like structure) Bract - floral floral lea leaff forme formed d at the base base of the flower or lower stalk. - small - protec protectt flower flower bud bud - in invo volu lucr cre e

Modified stem:

- rec receptacle- end of peduncle (floral stalk) - pedicel

Floral Variations: 1. Parts present a. Complete - flow flower ers s wit with h fou fourr modified leaves (petal, sepal, stamen and carpel b. Incomplete - lack lacks s any any of th the e modified leaves

2. Sexuality a. Perfect - bise bisexu xual al or hermaproditic - carp carpel el and and stam stamen en - an anim imal al polli pollina nate ted d b. Imperfect - un unis isex exua uall - carp carpel el or or stam stamen en - wi wind nd p poll ollin inat ated ed 2 types of imperfect flower: 1. pistillate  – female flower 2. staminate  – male flower

As to distribution of imperfect flowers plants can be: 1. monoecious 2. dioecious 3. polygamous 1. Monoecious - plant plant with bo both th imperfect flowers e.g. corn

2. Dioecious - imperf imperfect ect flowe flowers rs are borne in separate plants, so “male and female plants”.

pistillate

Staminate

3. Polygamous - pe perf rfec ectt an and imperfect flowers are found in the same plant

3. Fusion of flower parts a. Connation - parts parts of of a singl single e whorl whorl of modified leaves are fused together b. Adnation - one wh whorl orl of of modi modifie fied d leaves is fused with another whorl

4. Number of flower parts a. Dicotyledonous Dicotyledonous - flower parts in 4’s and 5’s or divisible by 4 or 5 ex. magnolia b. Monocotyledonous - flower parts are in 3’s or divisible by 3’s Patersonia

5. Nature of flowers a. Regular - pet petals als are of the the same same size and shape

b. Irregular - pet petals als are are diff differe erent nt in in size and shape

Irregular Flowers: 1. Papilionaceous a. standard/banner - large largest st ou oute termo rmost st showy petal b. wings or alae - tw two o late lateral ral pe peta tals ls c. kell or carina - inne innermo rmost st smal smalle lest st petals ex. blue pea Broom (Cytisus scoparius) 

2. Caesalpinaceous - flowe flowerr consis consists ts of 5 petals a. banner - smalles smallestt innermo innermost st petal b. 2 wings c. 2 keels same size and shape ex. caballero

3. Bilabi Bilabiate ate (2- lipped lipped)) - pe peta tals ls are are parti partial ally ly united - partia partially lly united united pet petals als form the upper and lower lips ex. sky flower

4. Orchidaceous - flow flower er has has 3 pe peta tals ls labellum – petal which is entirely different in size and shape

6.Symmetry of flowers a. Actinomorphic - radial symmetry - flowe flowers rs can can be be divid divided ed into 2 equal halves along any plane b. Zygomorphic - bilater bilateral al symm symmetry etry - divided divided into into 2 equ equal al halves only by a medial cut through the central axis

7. Position of the ovary a. Superior ovary - pe peta tals ls and and sep sepals als inserted below the ovary - hypogynous b. Inferior ovary - pe peta tals ls and and sep sepal als s inserted above the ovary - epigynous

ovary

Superior ovary

Inferior ovary

8. Placentation placenta - tissue tissue where where ovules ovules are are attached inside the ovary

placentation - arrangemen arrangementt of placenta placenta in in the ovary

a. axile placentation b. parietal placentation c. marginal placentation d. basal placentation

Inflorescence or Anthotaxy - Flower clusters - differ in: a. number of flowers present b. sequence of floral maturity c. length of the pedicel d. number and arrangement of peduncles

Kinds of Inflorescences: 1. Raceme - un unbra branc nche hed d main main axis axis or peduncle - floret florets s matur mature e all all at the same time - pe pedi dice cels ls are are of of the the same length ex. gladiola, corrales

pedicel

2. Panicle - branc branche hed d main main axi axis s or peduncle - flor floret ets s matu mature re at at the the same time ex. rice, cadena de amor

Branched peduncle

3. Spike - elon elonga gate ted d axis axis - sess sessilile e (wit (witho hout ut pedicel florets) ex.Seifritz’s flower 

4. Ament or catkin - specia speciall ty type o off spik spike e - elon elonga gate ted d axis axis hanging or drooping - flow flowers ers are are usu usual ally ly unisexual ex. buntot pusa

5. Spadix - fles fleshy hy spik spike e wit with h both male and female flowers - pe peta talllloi oid d brac bractt (spathe) ex. anthurium, gabi pongapong

Amorph Amorphoph ophallu allus s titanu titanum m The world’s largest flower  - spa spadix dix is is 46 46 iinc nche hes s tall! A rare plant of the Indonesia rain forest

6. Cyme - cent centra rall flow flower er opens first - pe pedi dice cels ls of younger flowers at the margin are longer than the older flowers at the center ex. Shanghai beauty santan, mayana

7. Corymb - simi simila larr wit with h cyme cyme - ped pedice icels ls of young younger er flower shorter (center) - pe pedi dice cels ls of olde olderr flower longer (margin or base) ex. caballero

8. Umbel - axis axis is sho short rter er - ped pedici icilla llate te flowe flowers rs radiated from the rounded apex of the axis ex. Japanese bamboo

Compound umbel

Simple umbel

9. Head or capitate - flowe flowers rs are sessile sessile (no pedicel) - arrang arrangeme ement nt of flow flowers ers similar to umbel - flowe flowers rs may may be of of 2 kind kinds: s: 1. disc flower - located located at the the cent center er 2. ray flower - located located at the the marg margin in ex. sunflower, cosmos

10. Fascicle - clos closed ed clus cluste terr or or small bundle of pedicelled or sessile flowers on one side of the stem ex. abaca, false birds of paradise

Thank you for listening. Ross D. Vasquez

Cross section of the ovule inside the ovary

Embryo sac with 8 nuclei

Pollen Pollen grai grainn- male male gameto gametoph phyt yte e

Tube nucleus nucl eus Generative nucleus

Mitosis Immature pollen grain

2 haploid sperm nuclei

Cell wall consists of:

Intine Exine  – with sporopollenin Pollen tube

Germinated pollen grain

End Thank you very much