Dr M’s favourite and recommended books on grass identification:
Dr M’s Agrostological training was honed by the marvellous volume entitled simply “Grasses” by Charles Hubbard (1954, 1968, 1984). Often affectionately referred to as “Hubbard“, i.e. “Let’s go and ID some grasses this weekend?”, “Yes! and don’t forget to bring Hubbard!” Hubbard’s keys were notoriously tough going, there was a key to grasses in flower, even a key to the “seeds” (caryopses) of grasses! But the most valuable for Dr M was Hubbard’s vegetative key to grasses. Also a bit of a struggle, but once important and mysterious characters such as “open sheath/closed sheath” were learned this was indispensable for identifying grasses without flowers – pretty much what the plant ecologist needs to do all the time! Recently Hubbard’s vegetative key has been superseded by the botanically life changing “Veg Key” by Poland & Clement (2009). This provides, at last, a really workable vegetative key to grasses as well as to the rest of the British flora!
Similarly, due to the troublesome keys and the out of date taxonomy Hubbard’s “Grasses” has recently been overtaken by “Grasses of the British Isles” by Tom Cope and Alan Gray (2009 – BSBI handbook No. 13) as the main up-to-date treatment of British grasses. However, although “Hubbard” is indisputably out of date taxonomically, there is still a place for him on the Agrostological shelves, because of the encyclopedic coverage including a standardised description for each species and, most valuable of all, a full page of illustration for each species. These illustrations include a line drawing of the whole plant as well as line drawings of all the important grass bits and pieces: the leaf blade, sheath, ligules and auricles (if present), stolons and rhizomes and of course the spikelet and its glumes, lemma, palea, caryoposis and lodicules! The new BSBI guide has super line drawings too, but not including the same level of detail as Hubbard. So, for example to distinguish species in a tricky genus like Agrostis, Hubbard reliably provides illustrations of lemmas and palea – the relative size of these two is important for distinguishing between Agrostis species. Cope & Gray fall a tad short here, since although their descriptions do deal with this, illustrations of these important parts of the spikelet are not provided.
Nonetheless, Cope and Gray is now without doubt the guide of choice for British grasses, being scholarly in its approach, beautifully written and illustrated with remarkably life-like line drawings by Margaret Tebbs. The taxonomy is up-to-date (some might argue with their treatment of Bromus but Dr M is happy that they retain Bromus without splitting into Anisantha, Bromus, Bromopsis and Ceratochloa as in the Book of Stace). The descriptions of each individual species include important details of structure, ecology and distribution. The greatest advance though, is in the keys. Cope & Gray recognise the short-coming in Hubbard’s keys and in their treatment they adopt the approach used by Clayton & Renvoize’s in their seminal work “Genera Graminum” (1986) by taking the tribe and genus as the working units. The key to the tribes is short (just over 2 pages) and the key to genera for each tribe equally short. This gives the user an opportunity to take a rest and to check the specimen against the tribe description before moving on to genus and then to species. Equally, if the user knows the genus then she can go straight to the key for that genus, thereby short-cutting a great deal of work! This repeated routine will, in time, enable the user to recognise tribes and so eventually cut out the first key (tribes). With Hubbard’s keys knowing the genus did not help to short-cut the key, since Hubbard’s keys are artificial and related species can not be relied upon to key out together.
Dr M has adopted Cope and Gray’s approach in his latest series of blog posts on the Tribes of grasses. Dr M encourages all those interested in grasses and grass identification to get your own copy of Cope and Gray and to get to know its format and keys and thereby enhance your agrostological development many-fold!
So far Dr M has posted on the Poeae, Aveneae, Bromeae, Triticeae and Brachypodieae, and there are more to come – watch this Agrostological space!
July 26, 2013
