Thursday, 21 January 2021

Hedypnois cretica

 Hedypnois cretica photos from Arrifana, Parque Natural Da Costa Vicentina,  Portugal.

Also known as Hedypnois rhagadioloides.

Note the stem thickens as it meets the capitula.

A lockdown task of looking through old photos and attempting to identify them was helped by the excellent web site Flora-On which covers the wild flowers of Portugal well. My interest in this particular species was driven by trying to find examples of the phyllaries ( involucral bracts) that show signs of swelling.  This seems to be a feature of many yellow composites including some Crepis and Sonchus species in the UK.

The phyllaries tend to swell as the achenes mature after the ligules have faded and may be some form of added protection to the achenes?

In the case of Hedypnois cretica the phyllaries are quite plump at an early stage as shown in the above photo.



In the photo above the ligules (petals) have faded and the achenes have developed their pappus hairs which stick out of the top. The  phyllaries have become more swollen which can be seen especially towards the tips compared with the previous photo. 


The third photo shows that the phyllaries in bud are not showing as much thickening.

Key features of Hedypnois cretica are the phyllaries being 'strongly incurved in fruit' which separate cretica from arenaria which also occurs in Portugal. Other features are the stems that thicken just below the capitula and in many plants, more than shown in these photos.

Hedypnois cretica is an annual plant with stems branched and many flower heads. Basal leaves may be present at flowering but on some plants I saw had already turned brown. Lower leaves can be entire to deeply lobed but in the case here were only shallowly lobed.  A variable feature.



The photo above shows a lower stem leaf with small lobes. Leaf is sessile (without a leaf stem) and has white simple hairs along the margin.


A mid stem leaf is clasping the stem, with auricles. The margin is showing the white hairs well.



Habitat was at the side of a track at Arrifana, on the West Coast of Portugal.

One of the most interesting features of H. cretica is one that the achenes share with Leontodon saxatilis, an outer row that lack the pappus hairs, which are replaced by short scales. This feature is shown on the Flora-On site.  https://flora-on.pt/#/1Hedypnois+cretica


Peter Leonard
Rampton, Cambridgeshire.
Jan 2021


 

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