A highlight of the BSBI ASM, Polygala amarella (dwarf milkwort)
Anyway, this last Sunday I finally managed to find some time in the diary for a recording meeting, and I met up with three other locals at Kiddington. Just in time I had been reminded by Sally Abbey that her recording group had already been there this season, so rather than repeat their work we recorded a tetrad to the east of Kiddington, taking in the lanes, farmland and woodland of Glympton (SP42G). It was a fairly ordinary square without the many lovely highlights of previous meetings this season, but we hit the target of 200 taxa that makes me feel like it was worth going out. A few odd things were found, mostly plants that are likely under-recorded.
One such was the hybrid bindweed Calystegia sepium x silvatica (=C. x lucana), which I am not sure I have ever noticed before. Apparently it is a variable hybrid, but our plants had large flowers like C. silvatica (large bindweed) but with the bracts below the flowers only slightly overlapping and not pouched (as they would be in C. silvatica), and the leaves small, intermediate in shape between C. sepium (hedge bindweed) and C. silvatica (the latter has a broad sinus with a truncate base, the former a narrow sinus with an acute base, as illustrated in Polland and Clement). Another odd plant was Bromus commutatus var. pubens, which looks all the world like the usual meadow brome (var. commutatus) but has shortly pubescent spikelets. As I have described in previous posts, B. commutatus is likely a common cereal weed in Oxon but is significantly under-recorded, probably because botanists think of it as a plant of meadows.
Finally, something must be said about the hedges in the Glympton area, as they were the worst I have seen in Oxon for in-filling and re-planting with alien shrubs sourced from nurseries that should know better. Mile upon mile was full of non-native dogwood and spindle and questionable field maple and hawthorn, presumably on land belonging to the same estate. The dogwood which was the main component of many hedges was a great beast with enormous leaves — I think it was Cornus koenigii (Asian dogwood), a first for the county, rather than the more usual C. sanguinea subsp. australis from south-east Europe and which also often has large leaves. It'd be marvelous if other recorders could be mindful of alien shrubs in hedges and send me records. Planting these shrubs for housing, roads and other developments as well as countryside hedges has become very common and could come to affect our native scrub vegetation, so we need the records to understand potential future change. To encourage records, here's a key to Cornus taken from Sell and Murrell Volume 3.
| 1. | Hairs on underside of leaves mostly curved upwards and basifixed * | 2 |
| 1. | Hairs on underside of leaves mostly adpressed and medifixed ** | 3 |
| 2. | Leaves 4-9 x 2-6cm | C. sanguinea subsp. sanguinea |
| 2. | Leaves 5-13 x 2.5-7.0cm | C. koenigii |
| 3. | Leaves with 2–4 pairs of veins; drupes black | C. sanguinea subsp. australis |
| 3. | Leaves with 4–7 pairs of veins; drupes white or bluish *** | 4 |
| 4. | Twigs bright yellow or bright red in autumn and winter | 5 |
| 4. | Twigs becoming dark brownish-red in autumn | 6 |
| 5. | Twigs becoming bright yellow in autumn and winter | C. alba var. flaviramea |
| 5. | Twigs becoming bright red in autumn and winter | C. alba var. sibirica |
| 6. | Plant not stoloniferous; leaves 5–15 × 3–10 cm | C. alba var. alba |
| 6. | Plant stoloniferous; leaves 4–9 × 2.5–6.0 cm | C. sericea |
* Bend the top of the leaf over your finger and hold it up to the light - you will see the hairs sticking up. Under a lens the hairs look like they have one arm, or if there appear to be two it is two hairs arising from the same point rather than a single medifixed hair.
** Bend the top of the leaf over your finger and hold it up to the light - you will see no or few hairs. Under a lens the hairs look like they have two arms, with both mostly pressed against the leaf.
*** The two remaining species look very different from the previous three and populations are usually very obviously of horticulutral origin, e.g. landscape plantings, garden rubbish. C. sericea can be invasive of damp woodland.
