I’ve created a database for some 180 grasses, focusing on vegetative features because these are available for longer periods of the year than floral features in grasses. I’ve also added a couple of other options which will be useful for anyone managing turfgrass surfaces for either sports or general lawns and amenity surfaces.
The web application is functional and should only be considered as in trial form for the time being. However, the initial aim of creating something which can be readily used in the field (it is web responsive) and especially for learning purposes has been achieved, albeit taking a bit longer than planned.
There are some core options which are mostly consistent within each species (e.g. ligule type, auricle present or not, blade type – bristle or flat/rolled) and also other options which can be variable, such as hairiness of leaf or sheath, leaf width and other groups such as prominent ribs on the upper blade, or shallow ribbing. The categorisations are based on my own interpretation of data, so clearly there is room for disagreement as to what should, or should not, fall within a certain category, but that I suppose is a slight downfall of trying to introduce general categories to the natural world.
The main influencers of varying features are environmental conditions or the time of year so these would not be used for making key decisions, but they do complement the core ones and can be used to significantly narrow down potential options further. Caution though is the name of the game regards those more variable features. Always refer to a specialist botanical key to confirm or refute what you have identified using this key.
The data are (“is” sounds so much better but data is plural, so “are” it has to be) quite comprehensive, although I need to field test the web app, plus I will also be adding floral features later, as well as habitat data. Some of the data are incomplete, especially regards some of the transverse section of the young leaf in a shoot, which I need to investigate further.
Other major features to add will include images / diagrams of some of the grasses (probably those which are encountered within a turfgrass situation to start with) as well as a help key to explain terminology used.
For example, leaf width: ‘What do I mean by a ‘Fine’ leaf width? In my key this is any blade typically less than 1.5mm across, but this needs to be explained. So there is still a fair bit of work to do regards having well defined descriptions to help the user.
As mentioned above, for people involved with the maintenance of turfgrass surfaces, whether for sports or amenity lawns, I’ve also added a further feature which narrows down options to the more likely sown, naturalised or weed grasses that might be found. This is another artificial and generally subjective category but it will probably capture the vast majority; other grasses could quite easily encroach on turfgrass surfaces, especially the lesser maintained lawn areas.
My interpretation of a ‘maintained surface’ for this particular feature of the key is an area of grass which is mown regularly (say at least fortnightly, but in practice it will be much more often) and will have a mown height of say no more than 60mm (but in practice it will be less and more like a maximum of 40mm), meaning the maximum grass height would not get above 100mm at the most; but we are talking very general estimates here. It is just meant to indicate this part of the key is clearly meant for actively and regularly maintained turf.
With this being an ‘Open’turf site with a primary aim of it being ‘learning’ I think it is only reasonable that the work is licenced under the Creative Commons, which I have done.
A full list of references will be given in the follow-on blog article for the development of this ID Key.
Chris Gray, 21st January 2018