Here is one of my candidates for ‘most elegant of all British grasses’. It’s Apera spica-venti, and has a droopy, shining golden inflorescence, made up of tiny spikelets with ridiculously long awns.
It stands about 1m tall, and its considerable height means that the individual spikelets (less than 3mm long) look even smaller than they are. The awns can be up to 4 times this length (they are as much as10mm long and are seldom less than 5mm).
Apera is one of the genera where there is just 1 floret per spikelet, hidden completely by the glumes (Key F in Stace, with companions like Agrostis and Polypogon)
It is common only in eastern England and is found most often as a weed of winter cereal crops on dry, sandy soils. Its familiar name is highly descriptive: Loose Silky-bent.
It's fiddly, because all the parts are so small, but opening up the glumes with fine tweezers will expose the single lemma and palea and show the insertion of the the base of the awn just below the tip of the lemma.
This is one of Silwood Park's most notable rarities, and the great George Claridge Druce recorded the plant from Silwood in 1891. We dedicate the plot known as Ashurst Four Acre Field to its conservation: we cultivate the field each year in October, but don't sow a crop.
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This is what Ashurst looks like in a ‘ragwort year’. There are more than 10 flowering individuals per square metre.
This is what Ashurst looks like this year (1 August 2023). There’s not a single ragwort plant in sight.
So what is going on ? Between 1980 and 2019 ragwort numbers fluctuated dramatically but there were no extended periods of very low plant densities (less than 1 m-2). Since 2020 we’ve seen 4 consecutive years with exceptionally low numbers.
Identifying rushes. The three annual species of Section Tenageia can be tricky to tell apart. The common species is Juncus bufonius (left) and the two rarer species are J. foliosus (upper right) and J. ranarius (lower right).
They all have flat or inrolled bifacial (grass-like) leaves on the stem (the basal leaves are typically withered by flowering time). The diffuse panicle is interspersed with leaf-like bracts and each flower has 2 small bracteoles.
Juncus foliosus is the easiest to identify: its leaves are more than 1.5mm wide (left) and the seeds have longitudinal ridges (x20, right A).
Identifying rushes. The reason why our 31 Juncus spp. are so tricky to identify is that the genus is so complicated botanically. It’s worth starting by looking at each of the 10 Sections that are represented in UK, just so that you can see the issues involved.
Identifying grasses. It’s obviously a Brome, but which Brome is it ? First, we need to identify the genus (i.e. is it Bromus, or Bromopsis, or Anisantha or Ceratochloa ?). This is the lower half of Key H on p. 1033.
#6 Are the lemmas strongly keeled on the back (left) or not (right). Definitely not keeled, so on to #7
#7 Always a tricky one. Annual or perennial? Look at the roots and check for the absence of rhizomes. See if there are any non-flowering shoots. No rhizomes and no sterile shoots, so annual is the best bet. On to #10.
Seaside Grass Quiz. This is arranged by habitat (sand-dune, dune slack, rocks & shingle, cliff and tidal mud-flat) then by plant size within habitat (big, medium, small). Answers tomorrow.
Grass revision quiz. Waterside and wetland grasses. The are just 10 species in this quiz, reflecting the ecological fact that rushes, sedges and other Cyperaceae are more numerous than grasses in this habitat.