Clematis of the Month for February 2021
described by Brigitte Niemela
The flowers open very wide so that the white staminodes are visible
Different forms of Clematis ‘Frances Rivis’
When I first started researching for this article, I soon discovered that there wasn’t one C. ‘Frances Rivis’, but two. Depending on which country you live in, you will receive one or the other variety when you buy it.Obviously there is an English form and a Dutch form. Compared to the Dutch form, the flowers of the English form do not open as wide and tend to be rather violet than blue. The tepals are narrower and longer. The English form is probably C. ‘Blue Dancer’. This variety is quite common in England and France.In this article I will describe the so called Dutch form. Authors such as Magnus Johnson, Raymond Evison, F. M. Westphal and Wendy Wesley write that C. ‘Frances Rivis’ is the same clematis as C. ‘Blue Giant’.To make the whole thing even more complicated, there are different spellings such as C. ‘Francis Rivis’, C. ‘Francis Rives’ etc.
Origin of Clematis ‘Frances Rivis’
In 1966, the plant was first mentioned in the Bulletin of the Royal Horticultural Society when it was given an Award of Garden Merit. This was still under the original name, C. ‘Blue Giant’. It was a seedling from Mrs. Frances Rivis. A few years later (1968) it was renamed to honour its discoverer and from this time onwards it was C. ‘Frances Rivis’. Wendy Wesley explains this in detail in the RHS Plant Trials Bulletin for Clematis alpina & Clematis macropetala. There she also writes that the plant is probably a seedling from C. ochotensis.
Description
The flowers of C. ‘Frances Rivis’ have four gentian blue tepals and an inner ring of white staminodes which sometimes have blue tips 
C. ‘Frances Rivis’ is easy to guide along a fence 
The buds are acutely ovate, this means they are
sharply pointed but not drawn out
In my climate we sometime have snowfall in April when C. ‘Frances Rivis’ is already in flower – it doesn’t worry it much and it keeps on blooming 
Lovely contrast between blue tepals and white staminodes
After comparing many photos and descriptions, I am sure that the plant in my garden is the Dutch form.
C. ‘Frances Rivis’ is a deciduous, vining clematis and belongs to pruning group 1. Pruning is not necessary. However, it can be pruned after flowering if it has grown too big. A more severe pruning every couple of years will keep it from aging too much.
It grows to about three meters (10 feet) high. Like other Alpinas, it is well suited to be trained horizontally along a fence. My heavy, loamy soil doesn’t really appeal to the Alpinas, though C. ‘Frances Rivis’ copes relatively well with these conditions compared to other varieties. However, when planting, I make sure that waterlogging is absolutely prevented. To do this, I work in sand and expanded clay pellets as drainage. If its feet don’t get wet, it can even be planted in shady spots.
In full bloom, C. ‘Frances Rivis’ has a striking appearance due to the strong contrast between the blue of the tepals and the white inside. The nodding, bell-shaped flowers are relatively large for an Alpina. They measure 5 – 8 cm (2-3 in) across. Initially the four gentian blue outer petals, which botanists call tepals, enclose the inner part of the flower. They form a acutely ovate bud. Later they open very wide so that the white inside of the flower is visible. These are the so-called staminodes, i.e. rudimentary stamens that have lost their function and look more like petals. Sometimes there are also somewhat longer staminodes that are white at the base and blue at the tips. After flowering, seed heads develop, which contribute to the attractiveness of the climbing plant for a longer period of time. The leaves are light green, bipinnate and obtuse toothed.
C. ‘Frances Rivis’ in a bouquet with tulips and muscari 
C. ‘Frances Rivis’ in a bouquet with Narcissus ‘Cheerfulness’ and muscari
Résumé
Undoubtedly, it speaks for the quality of a plant if it has been awarded the Award of Garden Merit for over half a century. C. ‘Frances Rivis’ is a robust and vigorous plant and is therefore also recommended for beginners. It enriches every spring garden with its blue flowers.
Bibliography:
- Beutler, Linda, The Plant Lover’s Guide to Clematis
- Chesshire, Charles, Das große Buch der Clematis
- Evison, Raymond J, Clématites du 3e millénaire
- Howells, John, The Rose and the Clematis: As Good Companions
- Johnson, Magnus, The Genus Clematis
- Travers, André und Willery, Didier, Clématites. Bien les utiliser au jardin
- Toomey, Mary, Clematis
- Westphal, Friedrich Manfred, Hauptkatalog Clematis
- http://www.clematis.hull.ac.uk/new-clemdetail.cfm?dbkey=33
- http://www.clematis.hull.ac.uk/new-clemdetail.cfm?dbkey=1862
- https://www.rhs.org.uk/plants/pdfs/plant-trials-and-awards/plant-bulletins/clematis-alpina-and-clematis-macropetala.pdf
Brigitte Niemela