Yellow Pimpernel (Lysimachia nemorum)

Family: Primulaceae

Common name: Yellow Pimpernel

Scientific name: Lysimachia nemorum

Date taken: 1/6/2024

Notes: Opposite-leaved prostrate plant. Hairless. This population was found on a stream bank.

Chickweed Wintergreen (Trientalis europaea)

Family: Primulaceae

Common name: Chickweed Wintergreen

Scientific name: Trientalis europaea

Date taken: 26/5/2024, 9/6/2024

Notes: A distinctive plant with a confusing name as it is neither a chickweed (Caryophyllaceae) nor a wintergreen (Pyrolaceae). Locally common in the Scottish highlands and is found across a wide range of environmental conditions from sunny spots to shaded understories.

Oxlip (Primula elatior)

Family: Primulaceae

Common name: Oxlip

Scientific name: Primula elatior

Date taken: 19/4/2023

Notes: Plant with a restricted geographical distribution. Compared with the more common Cowslip (Primula veris), flowers are paler with spreading corolla. Compared to False Oxlip (P. vulgaris x veris), flowers dip towards the same direction. Also note that the orange speckles on the corolla tube is much less prominent in Oxlip. 

Like other Primula spp., individuals produce one of two flower types - thrum flowers or pin flowers.

Cowslip (Primula veris)

Family: Primulaceae

Common name: Cowslip

Scientific name: Primula veris

Date taken: 9/4/2023

Notes: Common on meadows and grasslands. Not to be confused with Oxlip (Primula elatior), which has flowers that open more widely and paler flowers without prominent orange speckles. Like Primrose (Primula vulgaris), plants either produce thrum flowers with long stamens or pin flowers with long stigmas. Hybrids occur between P. vulgaris, P. elatior, and P. veris, which has intermediate characteristics.

False Oxlip (Primula vulgaris x veris)

Family: Primulaceae

Common name: False Oxlip

Scientific name: Primula vulgaris x veris = P. x polyantha

Date taken: 1/4/2023

Notes: Hybrid between Primrose (P. vulgaris) and Cowslip (P. veris). Like Cowslip, multiple flowers are found on the same flower stalk, but the plants are larger and corolla on flowers are spreading like that in Oxlip (P. elatior). Unlike the Oxlip, however, flowers are a darker shade of yellow, has orange speckles on corolla. Also differs from both the Cowslip and the Oxlip by having flowers pointing to different directions, but this is sometimes difficult to judge if the population is small.

Primrose (Primula vulgaris)

Family: Primulaceae

Common name: Primrose

Scientific name: Primula vulgaris

Date taken: 14/3/2023

Notes: 

Primrose is heterostylous. This means that some plants only produce pin flowers with long stigmas + short stamens, while others only produce thrum flowers with long stamens + short stigmas. The phenomenon has been noticed by Darwin, who hypothesised that the arrangement promoted cross-pollination between different plants. More recent research showed that heterostyly in primrose is controlled by a supergene called the S locus, which is absent in pin-flowered plants but present as one single copy (hemizygous) in thrum-flowered plants. 

This population was found scattered on chalk grasslands in South London. 

Reference: https://www.nature.com/articles/s41598-018-36304-4