angiosperm biodiversity

Question 1

angiosperm classification

Answer 1

• plant order names end ‘ales’
• plant family names end ‘aceae’
• 19 major families, 70% Ceridigion wildflowers
• family name often derived from first genus derived
• ‘taxonomic order’, families named in order of complexity, most similar families adjacent
• eudicots include Ranunculaceae, Caryophyllaceae, Fabaceae, Asteraceae
• monocots include Poaceae, Asparagaceae

Question 2

Ranunculaceae

Answer 2

• simplest eudicot
• aquatic plants including water-crowfoot, spearworts etc
• woodland plants including celandine, wood anenome etc
• simple floral structures
• relictual (ancestral) floral features
• many separate stamens and carpels
• low number of petals, crown of stamens, carpal in centre

Question 3

Caryophyllaceae

Answer 3

• some derived (advanced) floral features
• 5 bifurcated petals
• fewer carpels and stamens
• carpels fused in ovary
  e.g. stitchworts, campions, ragged robin

Question 3

Asteraceae

Answer 3

• largest eudicot family (second largest overall)
• many derived floral features
• compound flowers of ‘florets’ with own floral parts
• inferior ovaries
• e.g. dandelions, sunflowers

Question 3

Fabaceae

Answer 3

• third largest flower family
• all legumes
• some fix nitrogen via relationship with Rhizobium
• derived floral features
• zygomorphic petals (bilateral symmetry)
• specialised for hymenoptera, learnt behaviour to split petals to access reproductive parts
• e.g. gorse, peas, soya, peanut, clovers

Question 4

superior vs inferior ovaries

Answer 4

• superior ovaries (ancestral form), ovary sits above receptacle where the other floral organs attach
• inferior ovaries, ovary sits below/within receptacle, anthers closer to stigma

Question 5

Poaceae

Answer 5

• many derived floral features
• most wind pollinated
• composed of florets in which floral parts are enclosed in ‘bracts’
• most economically important family of plants
• e.g. wheat, maize, rice, sugarcane, bamboo, grasses

Question 6

Asparagaceae

Answer 6

• many derived floral features
• petals multiples of three (as monocot)
• e.g. bluebells

Question 7

new angiosperm classification, Eudicots

Answer 7

• basal angiosperms (e.g. Amborella) formerly both considered as dicots
• monocots and eudicots evolved from old ‘dicots’

Question 7

general differences between monocots and eudicots

Answer 7

• monocots have one cotyledon (early leaf from seed), eudicots have two
• monocots have parallel veins, eudicots have net like veins
• stems, vascular tissue scattered in monocots, arranged in a ring in eudicots
• roots fibrous in monocots, main tap root with lateral roots in eudicots
• flowers in multiples of 3 in monocots, multiples of 4 or 5 in dicots