Learn about the comparison between Orchidaceae and Asteraceae.
Comparison # Orchidaceae:
1. Habit-Plants terrestrial, often vinelike, mostly herbaceous, perennating by pseudo-bulbs; epiphytes, saprophytes or even parasites.
2. Stem-Stem with scattered vascular bundles.
3. Leaves-Simple, venation parallel.
4. Inflorescence-Solitary, raceme or spike.
5. Flower-Large, gaudy and of variable shape, trimerous, epigynous. All flowers irregular and zygomorphic.
6. Calyx-Well developed and coloured.
7. Corolla-Polypetalos.
8. Androecium-Stamens 3, one or two functional (though originally six) others reduced to staminodes, gynandrous, pollen forming pollinia.
9. Gynoecium-Pistil tricarpellary, syncarpous ovary inferior, twisted, unilocular, placentation marginal and parietal, ovules many.
Comparison # Asteraceae:
1. Habit-Herbs, erect, mostly terrestrial, annuals, autophytic.
2. Stem-Stem with vascular bundles in a ring.
3. Leaves-Simple, with reticulate venation.
4. Inflorescence-Capitulum.
5. Flower-Small, ray- and disc-florets, pentamerous, epigynous. Regular or irregular.
6. Calyx-Reduced forming pappus.
7. Corolla-Gamopetalous.
8. Androecium-Stamens 5, syngenesious, pollen powdery.
9. Gynoecium-Bicarpellary, syncarpous, ovary inferior, 1-chambered, basal placentation, single ovule.