Abstract
Summary. The study of cuticular structure as an aid to identification and classification, first extensively applied to fossil plants (particularly gymnosperms), is being increasingly used in recent taxonomic researches. The investigation of spodograms (the characteristic figures due to siliceous skeletons, crystals, and the like seen in the residue of leaves slowly reduced to ash) has proved of great value in the Gramineae especially, and among dicotyledons in the Urticales. Attempts to apply the method to fossil plants have not so far led to any results. Prat's analysis of epidermal characters in the Gramineae indicates the principles on which detailed taxonomic work should be based, and the systematic results he has so far obtained in this family are supported by evidence from other sources. Similar surveys of dicotyledonous families have scarcely yet been attempted; Bandulska's work on the Lauraceae is especially worthy of mention. The available evidence suggests that in cases of convergence of leaf form, structural differences in the cuticle will almost always provide a means of distinguishing isolated leaves. The distribution of cuticular elements may often furnish a means of discriminating closely related taxonomic groups which cannot be differentiated by purely structural characters. Statistical characters such as size or frequency of the elements, though often of value, must always be used with extreme caution. The ratio of stomata to epidermal cells (the stomatal index) is less variable than mere stomatal frequency. Individual cuticular and other epidermal characters cannot be considered in isolation in taxonomic work. As with other features used in classification, the sum of the available characters must be taken as the basis. The literature on fossil angiosperms, here summarised, is already extensive, particularly on the dicotyledons. Valuable results, however, can only be expected from full and detailed investigations of well‐preserved cuticles, together with a close comparison with a wide range of living forms.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 6
Claim · model-written summary
The stomatal index is less variable than mere stomatal frequency.
- Taxon
- ANGIOSPERMSMagnoliopsidat0
- Outcome
- stomatal indexe1
- Comparator
- stomatal frequencye1
Verbatim
t0“THE SYSTEMATIC VALUE OF CUTICULAR CHARACTERS IN RECENT AND FOSSIL ANGIOSPERMS”
e1“The ratio of stomata to epidermal cells (the stomatal index) is less variable than mere stomatal frequency”
Claim · model-written summary
In convergent leaf forms, structural differences in the cuticle will almost always distinguish isolated leaves.
- Taxon
- ANGIOSPERMSMagnoliopsidat0
- Outcome
- distinguishing isolated leavese2
- Qualifier
- in cases of convergence of leaf forme2
Verbatim
t0“THE SYSTEMATIC VALUE OF CUTICULAR CHARACTERS IN RECENT AND FOSSIL ANGIOSPERMS”
e2“The available evidence suggests that in cases of convergence of leaf form, structural differences in the cuticle will almost always provide a means of distinguishing isolated leaves”
Claim · model-written summary
The distribution of cuticular elements may often discriminate closely related taxonomic groups.
- Taxon
- ANGIOSPERMSMagnoliopsidat0
- Outcome
- discriminating closely related taxonomic groupse3
Verbatim
t0“THE SYSTEMATIC VALUE OF CUTICULAR CHARACTERS IN RECENT AND FOSSIL ANGIOSPERMS”
e3“The distribution of cuticular elements may often furnish a means of discriminating closely related taxonomic groups”
Claim · model-written summary
Statistical characters such as size or frequency of cuticular elements must always be used with extreme caution.
- Taxon
- ANGIOSPERMSMagnoliopsidat0
- Outcome
- Statistical characters such as size or frequency of the elementse4
Verbatim
t0“THE SYSTEMATIC VALUE OF CUTICULAR CHARACTERS IN RECENT AND FOSSIL ANGIOSPERMS”
e4“Statistical characters such as size or frequency of the elements, though often of value, must always be used with extreme caution”
Claim · model-written summary
Individual cuticular and other epidermal characters cannot be considered in isolation in taxonomic work.
- Taxon
- ANGIOSPERMSMagnoliopsidat0
- Outcome
- considered in isolatione5
Verbatim
t0“THE SYSTEMATIC VALUE OF CUTICULAR CHARACTERS IN RECENT AND FOSSIL ANGIOSPERMS”
e5“Individual cuticular and other epidermal characters cannot be considered in isolation in taxonomic work”
Claim · model-written summary
Investigation of spodograms has proved of great value in the Gramineae.
- Outcome
- investigation of spodogramse6
Verbatim
t0“THE SYSTEMATIC VALUE OF CUTICULAR CHARACTERS IN RECENT AND FOSSIL ANGIOSPERMS”
e6“The investigation of spodograms (the characteristic figures due to siliceous skeletons, crystals, and the like seen in the residue of leaves slowly reduced to ash) has proved of great value in the Gramineae especially”