Passiflora Society International

Cultivation, new species, new cultivars

PSI Officers

Management Committee

PSI is run by a Management Committee elected for a 3-year term from amongst its premium members; the current committee members were elected at the AGM on 22nd October 2022.

The committee then selects officers to fill particular roles from amongst its own ranks and those of premium and, in some cases, basic members. The current officers, appointed on 5th November 2022, are set out below; those asterisked are also members of the Management Committee.

Most of our officers have far too much to do, and some roles are currently vacant, so if you would like to help PSI in any capacity, formal or informal, please do get in touch with the Secretary – fresh blood is always welcome.

To contact a member of the committee or other officer, please click here.



President – John Vanderplank*

United Kingdom

John was born in Tanzania and spent most of his childhood in East Africa. He settled in the UK when his father retired. While still at school he started a small horticultural business, Greenholm Nurseries, with his father. On leaving school he studied commercial horticulture at the Somerset Farm Institute in Cannington.

His first encounter with passion flowers was strictly commercial with the nursery growing P. edulis and P. caerulea for the then fledgling garden centre trade. This proved so successful that the range of varieties was increased initially to six and then to ten.

In 1983, Roy Cheek (of what is now Plant Heritage) asked him if he would start a National Collection. By 1986 the collection boasted 150 species and cultivars and in 2004 John received the Brickell Award for Excellence in Cultivate Plant Conservation.

In 1991 his first book, Passion Flowers and Passion Fruit, was published and was followed by two later editions. In 2001 John was awarded a Ph.D. for his thesis on storage and conservation of Passiflora seed. While continuing this work he was made an Honorary Research Associate at the Royal Botanic Gardens, Kew.


Vice-President and Secretary – Robert Rice*

United Kingdom

Robert lives in Sussex in south east England, where he was born and given his first garden to look after when 10 years old. But it was not until many years later that he grew his first Passiflora, and only now he’s retired has he had the opportunity to focus on plants and horticulture in earnest.

Robert’s working life was spent developing computer software for business, and he now seeks to apply his skills to plant breeding, research and conservation. He has been Registrar since 2016, but will hand over to Christopher Taube in the first half of 2023. He is a former trustee of the conservation charity Plant Heritage which oversees some 650 collections in the British Isles.


Treasurer –  vacant (acting: Robert Rice*)

Applications are invited for this post as soon as possible.

In the meantime accounts have been prepared for each of the 2 years ended 31st August 2021 by Newsham Hanson, Chartered Accountants, UK and accounts for the year ending 31st August 2023 have also been prepared and presented to the 2023 AGM


Conference Organiser – Sergio Lloreda*


Sergio Lloreda Obolensky runs a family company that ships fresh exotic fruits from Colombia to customers worldwide. One of the company’s main products is passion fruit, including P. edulis, P. ligularis and P. mollissima. Passiflora have — without his being conscious of the process — become a healthy obsession which keeps his days full of activity: weekdays despatching passion fruit (a lot of work!) and weekends hiking round Colombia looking for different species. He feels he still has much to learn about this botanical genus and sometimes feel daunted with the immensity of the process.


Plant Conservation Officer – Markus Varga*


Markus has amassed an important data set on the representation of Passiflora species in major private collections. He is keen to extend this to institutional collections and use his knowledge to further PSI’s mission to conserve Passiflora species both in- and ex-situ.


American Seedbank Administrator – Bob Holzinger*

United States

Bob is a retired biochemist living in Carlsbad, Southern California where he has grown Passiflora and other tropical fruit for over 30 years


European Seedbank Administrator – Robert Dostal*


Robert lives in Öhringen, Baden-Württemberg, in South-Western Germany. In addition to maintaining and expanding his collection of Passiflora and breeding new cultivars, he has a particular interest in photography.


Registrar of Cultivars – Christopher Taube


Christopher has 16 years experience of horticulture. He is currently horticulturist at the Botanic Garden, Hamburg, with special responsibility for Passiflora and sub-tropical plants. He trained at the BS06 Vocational School, Hamburg


Newsletter Design Editor – Rob McPhail

United Kingdom and Netherlands

Rob hails from Scotland but has lived in the Netherlands for many years, where he is a keen grower of Passifora species and creator of new hybrids. He is a former President of PSI.


Newsletter Commissioning Editor – John Vanderplank*

see above


Newsletter Copy and General Editor – vacant (acting: Robert Rice*)


Web Administrator – vacant (acting: Robert Rice*)