Thorow-wax - Bupleurum rotundifolium

Description

A strong growing plant with alternate leaves. There is one leaf per node along the stem and the leaves are extended at the base to encircle the node, so that the stem apparently passes through it (perfoliate).

Similar Species

Other rare Bupleurum species may turn up - B falcatum, B baldense and B subovatum have all been recorded in VC55.  B subovatum is an occasional bird-seed alien and is grown in gardens; it is similar to and often mistaken for B rotundifolium. 

Identification difficulty
ID guidance

Yellow flowers; leaves simple and entire and less than twice as long as wide (B subovatum leaves are mostly more than twice as long as wide).  Fruits are smooth between ridges and umbels have 4-8 rays.  B subovatum fruits are papillose (with small nodules or pimples) and umbels have 2-3 rays. 

Recording advice

A photo of the plant in habitat, plus details of leaves, and flowers/fruits

Habitat

Thorow-wax was formerly an arable weed of chalk and limestone soils, but it is now a rare bird-seed casual or ornamental escape.

When to see it

To follow

Life History

Annual.

UK Status

Uncommon with only occasional scattered records in England and Wales.

VC55 Status

Rare in Leicestershire and Rutland where there are few recent records. There were no confirmed records resulting from the 1979 Flora survey of Leicestershire.

In the current Checklist (Jeeves, 2011) it is listed as Alien, archaeophyte; recorded from 20 localities.

It is on the VC55 Rare Plant Register

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Leicestershire & Rutland Map

MAP KEY:

Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015

UK Map