1A. Leaves needle-like; stems woody……………………………………………………………………………. Plant 1
1B. Leaves with flattened blade, simple or lobed; stems herbaceous……………………………………………… 2
2A. Leaves deeply lobed; stamens numerous; petals purple……………………………………………… Plant 3
2B. Leaves unlobed; stamens 2-6; petals white or absent………………………………………………….. 3
3A. Flowers either staminate or pistillate on separate inflorescences; petals absent….. Plant 4
3B. Flowers perfect; petals 4, white………………………………………. Plant 2
A. Bark present; leaves needle-like – Plant 1
A’. Bark absent; leaf with blade – go to B
B. Perianth absent, flowers in catkins – Plant 4
B’. Perianth present; flowers single or in a raceme – go to C
C. Flowers white; single pistil – Plant 2
C’. Flowers violet; many pistils – Plant 3
A Plant has cone -plant 1
A1 Plant has flower
B1 Flower has white petal-plant 2
B2 Flower has purple petal-plant 3
C1 Flower has no petal
A. Coniferous plants…Plant #1
A’. Herbaceous plants
B. Leaves compound… Plant #3
B’. Leaves simple
C. Leaves opposite…Plant #4
C’. Leaves alternate…Plant #2
Shellie Tabb
Dichotomous Key
A Plant has no flowers (PLANT 1)
A1 Plant has flowers with petals white or purple
B Plant has flowers with white petals (PLANT 2)
B1 Plant has flowers with purple petals (PLANT 3)
C Plant has flowers with no petals (PLANT 4)
A. The plant has needles (Plant 1)
A’. The plant has leaves – B
B. The plant has no petals (Plant 4)
B’. The plant has petals – C
C. The plant has white petals (Plant 2)
C’. The plant has purple petals (Plant 3)
Plant dichotomous key
Plant 1
Needles
Cones
Woody stem
No flowers
Plant 2
White flowers
4 petals
Plant 3
Purple flowers
Plant 4
Flower
No petals
A. Plant has no flowers (Plant 1)
A’. Plant has flowers
B. Plant has no petals (Plant 4)
B’. Plant has petals
C. Plant has white flowers (Plant 2)
C’. Plant has purple flowers (Plant 3)
Module 2: Dichotomous Key BIOL F195 – 2020 Hufford
A. Trees with woody stem, needle-like leaves, cones……………….…………Plant 1
B. Herbaceous plants , non-woody stem
a. Flowers white, whorled leaves with alternate arrangement on flowering stalk, star-shaped (stellate) hairs…………………………………………………………………………….Plant 2
a. Flowers purple, elongated sepals with fine hairs, multiple yellow-green anthers, purple stigmas………………………………………………………………………………………..Plant 3
b. Flowers apetalous, multiple combined anthers or stigmas, leaves pubescent….Plant 4
Dichotomous key
A: Conifer—Bin 1
A’: Not a conifer
B: Purple Flowers—Bin 2
B’: Not purple Flowers
C: Yellow flowers—Bin 3
C’: Other colored flowers—Bin 4