Extant Plants Databases

There are historic collections of rhododendrons, camellias and magnolias across the United Kingdom, some dating way back into the nineteenth century. 
Fashion, World Wars, economic ups and downs, disease and simple old age have all been contributors to the decline of some of these collections and as a result historic varieties have already disappeared or are at risk now. 
The RCM Hub has conservation at the heart of its objectives and our work is dedicated to preserving our heritage of these three genera.

• gathering data into a meaningful list which identifies threatened varieties
• organising propagation of those threatened varieties

Our philosophy is that conservation is all about saving plants regardless of their commercial merit:

• collections in the wild are no longer possible so it is our duty to ensure what we have is preserved
• the hybrids our forebears raised over nearly two centuries represent an historic record which should be as complete as possible

Database of Extant Rhododendrons, Camellias and Magnolias 

The first step towards realising our ambitions is to learn what is still in cultivation; only then can we know what we have lost. Luckily, we have excellent historic records to help us better understand the situation.

For the last eight years we have been assembling a list of extant plants of our three genera. Data is drawn from botanic and other major publicly accessible gardens, from private collections and from the general public who volunteer the information when they hear of our work. Checked carefully for naming against the international registers, we can determine rarity and assess the need for propagation to ensure a robust population is in existence. 

UPDATE July 2026:

This is a work in progress but the database currently records:

• 11,875 rhododendron hybrids including 3,982 cultivars of which 2,046 are ‘one offs’
• 5,950 rhododendron species including 486 species and 2762 subspecies and named selections of which 1,821 are ‘one offs’
• 7543 camellia hybrids including 1,812 cultivars of which 719 are ‘one offs’*
• 3,858 magnolia species and cultivars, including 137 species and named selections and 424 cultivars of which 304 are ‘one offs’

* The camellia species list is still being created and will appear in due course 

More entries to the rhododendron species database will be added in the near future together with a separate database of Vireya rhododendrons, species and cultivars.
All of the database lists are being updated continuously and revised as appropriate; updated reports will be published here.
As well as identifying rarity, rhododendrons, camellias and magnolias ‘lost’ from the gardens where they were raised are being identified, propagated and returned.

Help us to expand this database by sending a list of the rhododendrons, camellias and magnolias you grow to info@rcmhub.uk

Conservation through identification
Maybe you have rhododendrons, camellias or magnolias in your garden you don’t know the name of and would like to. Maybe your garden contains plants of great age and there could be something rare or important growing there?

How can we help you?
Sadly, we aren’t able to come to your garden to identify what you are growing but if you send us high resolution photographs of flowers, leaves, bark and the whole plant, and tell us what size these features are we will then do our best to identify them for you and give you an idea of their importance. Please send to info@rcmhub.uk