Biology
Flowering plant families
Flowering plants are divided into two classes.
- Dicotyledons: the seed has 2 cotyledons, a taproot, leaves with net venation, and flowers with 4-5 parts.
- Monocotyledons: the seed has 1 cotyledon, Monocot: fibrous root, leaves with parallel or arc venation, and flowers with 3 parts.
Dicotyledon families: Brassicaceae (4 petals arranged in a cross shape), Rosaceae (apple, pear, apricot), Fabaceae (butterfly-shaped flower, fruit is a legume), Solanaceae (tomato, potato), Asteraceae (flower head inflorescence).
Monocotyledons: Poaceae (spike inflorescence, fruit is a grain) and Liliaceae (onion, tulip).
| Family | Representative | Fruit |
|---|---|---|
| Brassicaceae | cabbage, radish | silique |
| Fabaceae | pea, bean | legume |
| Solanaceae | tomato | berry |
| Rosaceae | apple, pear | pome |
| Poaceae | wheat | grain |
Key facts
- Floral formula of Brassicaceae: *Brassicaceae: Ch₂₊₂ L₄ T₂₊₄ P₁. Fruit of Brassicaceae is a silique or silicle (radish, cabbage, mustard).
- Fabaceae: ↑Ch₍₅₎ L₁₊₂₊₍₂₎ T₍₉₎₊₁ P₁. Nodule bacteria on the roots (nitrogen fixation). Fruit of Fabaceae is a legume.
- Solanaceae: *Solanaceae: Ch₍₅₎ L₍₅₎ T₅ P₁. The fruit is a berry (tomato) or a capsule (tobacco).
- Rosaceae: *Ch₅ L₅ T∞ P∞. The fruit is a drupe (apricot), a pome (apple), or an aggregate of drupelets.
- Poaceae: the stem is a culm, Fruit of Poaceae is a grain. Liliaceae: *P₃₊₃ T₃₊₃ P₁. In this formula P has two meanings: the first P₃₊₃ is the perianth (3+3 tepals), and the last P₁ is the pistil.
- Letters: Ch calyx, L corolla, T stamen, P pistil.
Solanaceae: berry, Rosaceae: pome.