Passiflora Society International

Cultivation, new species, new cultivars

PSI Officers

Management Committee

PSI is run by a Management Committee elected from amongst its premium members; the current committee members were elected at the Inaugural Meeting of New PSI on 12th October 2019.

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, also appointed on 12th October 2019, are set out below; those asterisked are also members of the Management Committee.

If you wish to contact one of them, 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 start plant breeding in earnest. His goal is to produce beautiful passionflowers with fruit that is good to eat and which are hardy in south east England.

Robert’s working life was spent developing computer software for business, and he is keen to make that skill available to plant breeding, research and conservation. So he was delighted to take on the role of Passiflora Registrar in 2016, and has already set up a new website for that purpose – which he hopes to turn it into an on-line repository of information about the individual taxa.

In 2016 he became a trustee of the conservation charity Plant Heritage which oversees some 650 collections in the British Isles, for whom he produced a comprehensive review of their information management and technology, which he hopes will lead to their 100,000 taxa being available not just to local visitors but on-line browsers anywhere in the world. He has now stepped down from this post.


Treasurer –  Stefania Mattiuzzo*


Stefania’s day job is as an accountant, managing a group of people in the accounts department of a company; but her main hobby, which over the last 10 years has almost become a job in itself, is Passiflora.

She has a substantial collection, with other rare and unusual plants as well, to which she is constantly adding by her breeding activities.  She has created around 30 new hybrids, some now widely distributed in Italy, Europe and further afield. Current challenges include persuading Tacsonias  to put up with the USDA 9A climate of the coastal zone near Rome where she lives, and at the other extreme selecting cold hardy varieties for their flowers and fruit.

She loves sharing her expertise with others, and the Italian group she founded, Passiflore ed Altre Piante Insolite, now has some 2000 members, of which she is very proud. She also writes for a monthly Italian gardening magazine, participates in flower shows, and collaborates with the Istituto Regionale per la Floricoltura, Sanremo, and dreams one day of doing full time research.


Seedbank Administrator – Salvatore LaDelfa*

Italy and United Kingdom

Sal was born in Italy but now lives in Bedford, England. His goal is to produce Passiflora that are hardy in the cold Northern climate which has become his home !


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.


Newsletter Editor – Mattias Lanas

United States and Colombia

Mattias Lanas has a background in Earth systems science and fine art, which led to his current career of science illustrator. In addition to designing the PSI newsletter, Mattias teaches art classes, leads field sketching trips, and works on illustration commissions. He first fell in love with Passiflora when he stumbled upon a P. caerulea, and has since been hooked! Today, his interest in the genus is primarily in species taxonomy and conservation. When not in his studio Mattias can be found exploring Colombia (where he is based) for Passiflora, reading about insects, or doing pottery.


Newsletter Commissioning Editor – John Vanderplank*

see above


Registrar – Robert Rice*

see above


Web Administrator – tbc (acting: Robert Rice*)


Social Media Content Manager

Vacant – please volunteer if you have time and skills !


Social Media Liaison Officer – Salvatore LaDelfa*

see above