D³ database

Fruit Typology

Summary

 

FRUIT TYPOLOGY is a categorical trait which describes ecological characteristics of the fruit that are related to seed dispersal.

 

 

Trait description

 

FRUIT TYPOLOGY (column code: FRUIT_TYPE) is coded as one of the categories listed in Tab. 1. The coding scheme has two hierarchical levels with the first level mainly focusing if the fruit opens or stays closed during seed ripening and dispersal, whereas the second level addresses how the pericarp is constructed or opens.

In case of compound fruits or if fruits include additional structures (up to the whole infructescence), the whole structure is addressed if it affects seed dispersal, especially interactions with animals. For instance, Fragaria vesca with nutlets (i.e. several indehiscent hardcoated fruitlets) and Rubus idaeus with drupelets (i.e. several indehiscent fruitlets with fleshy mesocarp) are both categorized as fleshy fruits.

Species with more than one fruit type (e.g. Rosa species in which the complete rose hip may act as a fleshy fruit or it may open later, set the nutlets free and thus act as a dehiscent fruit) are marked as 'heterodiaspore' (see Heterodiaspory).

 

 

 

Tab. 1. Categorization of ecological fruit types

No.

Category

Description and examples


1

indehiscent fruit

The pericarp is not opening during ripening.

This category is only used if it is not possible to address the subordinate hierarchical level.

1a

non-fleshy indehiscent fruit

Indehiscent fruits with a hard or woody pericarp.

 

E.g. Poaceae, Asteraceae, Quercus, Ranunculus

Quercus robur - infructescence with three nuts.

1b

fleshy fruit

Indehiscent single or compound fruits with a fleshy pericarp independent of the ontogenetic origin of the fruit flesh.

 

E.g. Malus, Prunus, Rubus, Fragaria

Rubus fruticosus agg. - Fruit is built from many drupelets.

1c

pepo

Indehiscent fruits with coriaceous or solid paring and a fleshy inner layer.

 

E.g. Citrus, Cucurbita

Cucurbita pepo - The fruit has a solid paring.

2

dehiscent fruit

The pericarp opens during ripening and the seeds typically act as the diaspores. Dehiscent fruits include e.g. follicles, capsules, legumes or siliques.

This category is only used if it is not possible to address the subordinate hierarchical level.

2a

fruit with upright aperture

 

Dehiscent fruits with typically a small aperture located at the upper (distal) end. This position may allow seeds to stay for a longer time in the open fruit.

 

E.g. Papaver rhoeas, many Caryophyllaceae, Saxifragaceae

Silene noctiflora - Seeds are released from the opened capsule through the upright aperture.

2b

fruit with lateral aperture

Dehiscent fruits with typically a large aperture located lateral or basal. This position may allow seeds to be released fast. However, the seeds may also stay longer, e.g. if they are tightly connected to the fruit.

 

E.g. many Brassicaceae, Fabaceae, Scrophulariaceae, Epilobium

Laburnum anagyroides - legume, already opened at front and back seams of the carpels with seeds still attached to the fruit that has a lateral aperture.

3

explosive release mechanism

 

Indehiscent or dehiscent fruits with an explosive release mechanism.

 

E.g. many Cardamine, Euphorbia, Geranium, Impatiens

Geranium sanguineum Geranium sanguineum - fruit before (left) and after (right) explosive seed release.

4

gymnosperme type

Gymnosperm seeds with or without hull structures.

 

Gymnospermes, e.g. Abies, Pinus, Juniperus, Taxus

Larix decidua - cone with many winged seeds (not visible), which act as diaspores.

5

other

Fruit types that are not covered by one of the above mentioned categories.

 

6

not applicable

Reserved for

a) species that typically do not produce diaspores, e.g. the sterile hybrid Betula x aurata,

and b) for vegetative diaspore types, e.g. some species from the grass genera Poa, Deschampsia.

Poa alpina - The spikelets are transformed into vegetatively produced bulbils which rapidly start their development (pseudovivipary).

Data sources

 

FRUIT TYPOLOGY was categorized by visual inspection of fruits or respective images in addition to an intensive literature and web research.

 

 

Selected literature

 

Bojňanský, V. & Fargašová, A. (2007): Atlas of seeds and fruits of Central and East-European flora. The Carpathian Mountains region. Springer, Dordrecht.

 

Brouwer, W. & Stählin, A. (1975): Handbuch der Samenkunde für Landwirtschaft, Gartenbau und Forstwirtschaft. DLG-Verlag, Frankfurt.

 

Graf, J. et al. (1987): Tafelwerk zur Pflanzensystematik. Einführung in das natürliche System der Blütenpflanzen. Springer-Verlag.

 

Hegi, G. (1908ff): Illustrierte Flora von Mittel-Europa. Mit besonderer Berücksichtigung von Deutschland, Oesterreich und der Schweiz. Zahlreiche Bände in drei Auflagen. J. F. Lehmanns Verlag, 2. und 3. Auflage bei Paul Parey und Weissdorn-Verlag.


Hilger, H.H. & Hoppe, J.R. (1995): Die morphologische Vielfalt der generativen Diasporen – Präsentation eines Lehr- und Lernschemas. Feddes Repertorium 106, 503-513.

 

Müller-Schneider, P. (1977): Verbreitungsbiologie (Diasporologie) der Blütenpflanzen. Veröffentlichungen des Geobotanischen Institutes der ETH, Stiftung Rübel 61.

 

Müller-Schneider, P. (1986): Verbreitungsbiologie der Blütenpflanzen Graubündens. Veröffentlichungen des Geobotanischen Institutes der ETH, Stiftung Rübel 85.

 

Otto, B. (2002): Merkmale von Samen, Früchten, generativen Germinulen und generativen Diasporen. In: Klotz, S., Kühn, I. & Durka, W. [Hrsg.] (2002): BIOLFLOR - Eine Datenbank zu biologisch-ökologischen Merkmalen der Gefäßpflanzen in Deutschland. - Schriftenreihe für Vegetationskunde 38, Bonn: Bundesamt für Naturschutz, 177-196.