More from @crawley_mick

Mick Crawley

Jul 15

Grass revision quiz. Roadside, railway and waste ground grasses. There is only one properly droopy species in this list (the rest are upright) divided into 3 categories by the height of the flowering stem (tall (>1m), medium (30cm-99cm) and short (less than30cm) ). Answers later.

Tall 1.

Tall 2.

Read 23 tweets

Mick Crawley

@crawley_mick

Jul 11

Identifying grasses. This is one of the most delicately beautiful of all of the grass-weeds of cereal cultivation. The tall, droopy inflorescence has a delightful metallic-golden sheen.

Carefully open up the glumes and look inside. You will see that there is just one perfectly bisexual floret, so we need to be in Key F (Stace, p. 1030). The lemma awn is sub-terminal and the palea is thin and transparent.

). We’ve been in Key F before, so we can quickly eliminate Eriochloa, Leersia, Lagurus, Polypogon, Nassella, Stipellula, Celtica, and Stipa starting in earnest at #10.

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Mick Crawley

@crawley_mick

Jun 24

Identifying grasses. There are 9 species of Festuca in the “ovina group” and they present a daunting challenge for beginners: F. brevipila, longifolia, glauca, vivipara, filiformis, ovina, lemanii (left), armoricana and huonii (right).

It’s a help that there are a few easy ones that can be dealt with quickly. The commonest proliferating grass that you will find in the uplands is Festuca vivipara. Apart from its proliferating (‘viviparous’) flowers, it’s just like the ubiquitous F. ovina.

A very blue-leaved tussock plant on pavements in town is likely to be Festuca glauca, self seeded from a nearby grass garden. The leaves have 4 (not 2) adaxial grooves, very short pedicels (0.3-0.5mm (right), not 0.5-1.8mm) and a hairy leaf sheath.

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Mick Crawley

@crawley_mick

Jun 18

Identifying grasses. This is a huge tussock-grass of wet woodland rides (often with Carex pendula) and moist grassland, with beautiful droopy panicles with a silver or golden metallic sheen. Numerous cultivars are used by gardeners in modern herbaceous perennial bedding schemes.

Here are its measurement data. Be carful how you handle the plant: its leaf edges are razor-sharp.

This is an example of a genus where you won’t know how many florets there are per spikelet until you have peeled back the glumes and had a close look inside (there are 2 florets per spikelet). While looking inside (x20), note that the lemma-awn is dorsal and basally inserted.

Read 12 tweets

Mick Crawley

@crawley_mick

Jun 16

Identifying grasses. On the heath, there’s a plant doing an impersonation of Festuca at the moment. It has a dense tussock of blue-grey, hair-like leaves (left) and a pale purple panicle of tiny spikelets, tightly contracted at first, then opening up (right) then closing again.

But what genus is it? Let’s begin by finding out what Group it’s in. It is none of the usual suspects (bamboo, maize, etc), it doesn’t have a hairy ligule or ovary, it’s not a Finger Grass or a spike, so we’re down to #12. Here are the measurement data.

#12 Since the spikelets are so tiny (all you can see are 2 glumes) the question is hard to answer in the field. The trick is to have tweezers with you and use them to give the glumes a firm squeeze. This will open them up so that you can look inside (x20): 1 floret means Group F.

Read 11 tweets

Mick Crawley

@crawley_mick

Jun 13

Identifying sedges. We’re at the seaside again. Non-droopy female spikes means Key F. We know enough already to skip quickly over Carex pallescens, flacca, riparia, rostrata, vesicaria and acutiformis, and start in earnest at #9 because the lowest bract is sheathing (right).

#9 The stems are densely tufted, so on to #14

#14 This is about how close-set or widely-spaced the female spikes are. Are more than half of the female spikes close to the terminal male spike (left) or at most 1 female (right). Ensure you understand what is meant here. We have 2 of 3 female spikes close to the male: on to #15

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