Dichotomous Key for Common Fruit

 

1. Fruit from one ovary of one flower ........[Simple Fruit].... 2

1. Fruit from more than one ovary, or more than one flower .... 17

 

2.   Fleshy at maturity ....................................... 3

2. Dry at maturity .......................................... 8

 

3. Single large hard seed, a "stone" fruit ................. Drupe

3. More than one seed, seed not enlarged and hardened .......... 4

 

4.   Seeds in a single linear order, separating from ovary wall,

forming a pod ....................................... Legume

4.   Seeds not in a single linear order ....................... 5

 

5. Inner layer of ovary (endocarp) papery, forming a core ... Pome

5.   Endocarp fleshy ............................................. 6

 

6.   Outer layer (exocarp) thin, easily peeled off, not leathery ...................................................... Berry

6.   Exocarp thickened and leathery (modified berries) ........ 7

 

7.   Divided into sections w/ cross-walls, citrus ...... Hesperidium

7.   Interior not divided, exocarp a rind ..................... Pepo

 

8.   Dehiscent (splits open at maturity), usually many seeds .. 9

8.   Indehiscent (does not split open), usually one seeded ... 12

 

9.   Derived from a pistil with one chamber (locule) ............ 10

9.   Derived from a pistil with more than one locule ............ 11

 

   10.   Dehiscent along one side (suture) ................ Follicle

   10. Dehiscent along two sutures ........................ Legume

 

11. From two locules, separating at maturity ............. Silique

11. From more than two locules, or lid-like top .......... Capsule

 

   12.   Ovary wall extends to form a wing .................. Samara

   12.   Fruit not winged ....................................... 13

 

13. With many seeds in single linear order forming a pod .. Legume

13. Fruit with one seed, or not in single linear order ........ 14

 

   14.   Outer wall not especially thick or hard, fruit small ... 15

   14.   Outer wall hardened, fruit relatively large ............ 16

 

15. Seed not tightly attached to ovary wall ............... Achene

15. Seed fused to ovary, grains ........................ Caryopsis

 

   16.   Ovary hard throughout ................................. Nut

   16.   Middle of ovary fibrous, seed hardened .............. Drupe

 

17.   Derived from many ovaries of one flower ...... Aggregate Fruit

17. From many ovaries of more than one flower ..... Multiple Fruit