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Dr Colin Walker

Profile summary

  • Visiting Informal Academic
  • Honorary Associate
  • Faculty of Science, Technology, Engineering & Mathematics
  • School of Environment, Earth & Ecosystem Sciences
  • colin.walker

Professional biography

  • I am currently an Honorary Associate. My research interests are in biosystematics, biodiversity and conservation of succulent plants.
  • My passion in life is succulent plants that started as a school boy in 1967, when I grew a few plants on windowsills at my parent's house. Even at this early stage my interests were with the other succulents, mainly Adromischus, Aloe, Gasteria, and Haworthia. I now has a modest-sized greenhouse collection of succulents, with most of the major families of succulents represented; many tender plants, along with a collection of sansevierias, also occupy many windowsills in the house.
  • Over the years I have played various roles in the “succulent scene”. My involvement with the International Asclepiad Society started in 1977, since when I have been Treasurer, Membership Secretary, Chairman and Editor of the journal Asklepios. Editor of Bradleya, scientific Yearbook of the British Cactus & Succulent Society, 2001-2012. Currently chairman, British Cactus & Succulent Society (2013 to date). Recently became chairman of the British Cactus & Succulent Society's Research Committee.
  • A member of the International Organisation for Succulent Plant Research (IOS) and Fellow of The Linnean Society.
  • I have published many articles and papers in various succulent journals around the world. Contributed to the Illustrated Handbook of Succulent Plants (2001–2003) on families such as the Crassulaceae, Bombacaceae, Dracaenaceae, Nolinaceae, and Urticaceae, and I'm currently working on the revised second edition. 
  • In 2011 I co-authored Aloes - The Definitive Guide, co-published by The Royal Botanic Gardens Kew and The British Cactus & Succulent Society. This is a major volume dealing with a large genus of succulents, some of which, notably Aloe vera, are of major economic importance.
  • As well as growing and writing about succulents, my other passion is collecting literature on these plants, and I now has an extensive library of books, booklets, and periodicals, ranging from very technical monographs through to novels, children’s books and even comic books.
  • I’m married to Marjorie and we have a daughter, Amy.

                                                                                                                                       

 

Research interests

Present research interests are centred around the biosystematics, biodiversity and conservation of succulent plants, notably members of the genera Aloe and Agave. Current topics:

(1) Writing revised entries for the second edition of the Illustrated Handbook of Succulent Plants, a multi-volume, multi-author work to be published both online and in hardcopy by Springer, Berlin. My mains contributions are as follows:

Asparagaceae: Beaucarnea, Dasylirion, Dracaena, Nolina.

Laxmanniaceae: Cordyline.

Malvaceae: Adansonia, Cavanillesia, Ceiba, Pseudobombax.

Crassulaceae: Umbilicus.

Urticaceae: Laportea, Obetia, Pilea, Sarcopilea.

Asteraceae: Baeriopsis.

(2) The genus Aloe in Ethiopia and Eritrea. 

(3) Biodiversity of the genus Agave in Mexico and the Caribbean.

I have been an invited speaker at several international conferences including: the Cactus & Succulent Society of America, San Francisco (1995); the Cactus & Succulent Society of New Zealand, New Plymouth (2000); The Succulent Plants of Eastern Africa, Verbania, Italy (2002), the Cactus & Succulent Society of New Zealand, Auckland (2005), the Cactus & Succulent Society of New South Wales, Australia (2010), the Cactus & Succulent Society of America, Mid-western Conference, Boston (2010), the Cactus & Succulent Society of America, Austin, Texas (2011), the Haworthia Society (2019). 

Currently chairman of the British Cactus & Succulent Society's Research Committee, which awards research grants to support projects that provide new information on the biology, propagation or cultivation of succulent plants.        

 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Publications

Agave lophantha (2019-07)
Walker, Colin
New Zealand Cactus & Succulent Journal, 72(2) (pp. 15-17)
Kalanchoe arborescens - a Madagascan giant (2019-07)
Walker, Colin
Sedum Society Newsletter(130) (pp. 81-84)
Aloe elegans - an Ethiopian/Eritrean endemic? (2019-06)
Walker, Colin
Haworthiad, 33(2) (pp. 32-37)
Notes on the taxonomy, iconography, and ecology of Aloe pluridens Haw. (Asphodelaceae: Alooideae), an endemic species from southeastern South Africa (2019-05)
Walker, Colin C.; Smith, Gideon F. and Figueiredo, Estrela
Bradleya, 37 (pp. 60-72)
Two shrubby Madagascan kalanchoes (2019-02)
Walker, Colin C.
New Zealand Cactus & Succulent Journal, 72(1) (pp. 5-9)
Caputia tomentosa (2019)
Walker, Colin; Smith, G.F.; Crouch, N.R. and Condy, Gillian
Flowering Plants of Africa, 66 (pp. 168-178)
Aloe erensii, Aloe jucunda and a new cultivar (2019)
Walker, Colin C. and Mace, Suzanne
CactusWorld, 37(1) (pp. 13-19)
Aloidendron barberae (2019)
Walker, Colin; Smith, G.F.; Figueiredo, E.; Klopper, R.R.; Crouch, N.R. and Condy, Gillian
Flowering Plants of Africa, 66 (pp. 8-21)
Aloe bakeri - a critically endangered highly localised Madagascan endemic (2019)
Walker, Colin
CactusWorld, 37(3) (pp. 181-186)
Flowering of Agave nickelsiae (2018-12)
Walker, Colin C.
CactusWorld, 36(4) (pp. 290-291)
Two rare Bolivian endemic cacti (2018-12)
Walker, Colin C.
New Zealand Cactus & Succulent Journal, 71(3) (pp. 14-17)
Aloe littoralis - a review of this widespread African species (2018-10)
Walker, Colin C.
Haworthiad, 32(3) (pp. 60-64)
Two choice African Sansevierias: S. hargeisana and S. hallii (2018-06)
Walker, Colin C.
New Zealand Cactus & Succulent Journal, 71(2) (pp. 4-8)
Guest editorial (2018-06)
Walker, Colin C.
CactusWorld, 36(2) (p 88)
Aloe pearsonii - a unique species in habitat and in cultivation. (2018-03)
Walker, Colin C. and Vanden Bon, Alice
CactusWorld, 36(1) (pp. 33-40)
Echinocereus pensilis updated (2018-02)
Walker, Colin C.
New Zealand Cactus & Succulent Journal, 71(1) (pp. 14-15)
Stapelia gigantea - "der Goliath dieser Gattung" (2018)
Walker, Colin
Avonia, 36(2) (pp. 124-125)
The stapeliads of Philip Miller at the Chelsea Physic Garden (2018)
Walker, Colin C.
Asklepios, 125 (pp. 12-17)
Two stapelias: Stapelia gigantea and S. schinzii var. angolensis (2017-12)
Walker, Colin C.
New Zealand Cactus & Succulent Journal, 70(3) (pp. 6-8)
Two architectural agaves: A. victoriae-reginae and A. nickelsiae (2017-07)
Walker, Colin
Cactus and Succulent Journal of NSW, 31(1) (pp. 9-13)
Aloe tomentosa – eine Art mit ungewöhnlichen, behaarten Blüten aus dem Jemen (2017-07)
Walker, Colin C.
Sukkulenten, 103(7-8) (pp. 29-37)
Introducing the genus Phedimus (2017-06)
Walker, Colin C.
New Zealand Cactus & Succulent Journal, 70(2) (pp. 4-7)
A tale of two Ethiopian aloes: Aloe jacksonii & A. elkerriana (2017-06)
Walker, Colin C.
Haworthiad, 31(2) (pp. 31-32)
Aloe mitriformis subsp. distans: the small mitre aloe (2017-02)
Walker, Colin C.
New Zealand Cactus and Succulent Journal, 70(1) (pp. 4-7)
Aloe pulcherrima - a beautiful Ethiopian endemic (2017)
Walker, Colin C.
CactusWorld, 35(2) (pp. 131-135)
A new intergeneric hybrid: xGastonialoe 'Gordon Rowley' (2017)
Walker, Colin C.
CactusWorld, 35(1) (pp. 21-22)
Agave victoriae-reginae and its close relatives (2017)
Walker, Colin C.
CactusWorld, 35(3) (pp. 159-166)
My first flowering of Aloe reynoldsii (2017)
Walker, Colin C.
Haworthiad, 31(3) (pp. 70-71)
CactusTalk: More dragon tree tales (2017)
Walker, Colin C.
CactusWorld, 35(4) (pp. 287-288)
Aloe tomentosa - a species with unusual hairy flowers from the Yemen (2016-09)
Walker, Colin
CactusWorld, 34(3) (pp. 153-158)
Aloe vera on Lanzarote (2016)
Walker, Colin
New Zealand Cactus & Succulent Journal, 69(2) (pp. 20-23)
A couple of Curios (2016)
Walker, Colin C.
Northants News, 27(1) (pp. 5-7)
Beaucarnea updated (2015-09)
Walker, Colin
CactusWorld, 33(4) (pp. 267-272)
Eric Judd - South African Aloe artist (2015-03)
Walker, Colin and Smith, Gideon F.
CactusWorld, 33(1) (pp. 59-63)
Aloe succotrina (Asphodelaceae) (2015)
Walker, C. C.; Klopper, R. R.; Smith, G. F. and Condy, Gillian
Flowering Plants of Africa, 64 (pp. 26-40)
The origin and predominance of Aloe vera (2015)
Walker, Colin
CactusWorld, 33(4) (pp. 276-277)
Dasylirion wheeleri (2015)
Walker, Colin
Northants News, 26(3) (pp. 7-8)
Aloe hardyi - a rare South African cremnophyte (2014-12)
Walker, Colin
CactusWorld, 32(4) (pp. 289-292)
More changes in Haworthia. (2014-12)
Walker, Colin
CactusWorld, 32(4) (p 304)
More change in Aloe, Haworthia and their close relatives (2014-06)
Walker, Colin
CactusWorld, 32(2) (pp. 138-139)
All change in Dracaena and Sansevieria (2014-06)
Walker, Colin
CactusWorld, 32(2) (pp. 140-141)
All change in Aloe and Haworthia (2014-03-12)
Walker, Colin
Cactus and Succulent Journal of NSW, 29(4) (pp. 78-80)
The World's biggest cactus flowers (2014)
Walker, Colin and Thorburn, Marjorie
Northants News, 25(3) (pp. 12-13)
Aloe cremnophila and Aloe jacksonii - cliff-dwellers from the Horn of Africa. (2014)
Walker, Colin
Northants News, 25(2) (pp. 14-16)
All change in Aloe and Haworthia (2013-12)
Walker, Colin
CactusWorld, 31(4) (p 297)
Two Kenyan sansevierias of Peter Bally (2013-07)
Walker, Colin
Northants News, 24(2) (pp. 6-7)
A cholla cactus and a grasshopper (2012-12)
Walker, Colin
CactusWorld, 30(4) (pp. 233-234)
Agaves through the ages (2011-06)
Walker, Colin
Cactus and Succulent Journal of NSW, 27(8) (pp. 153-156)
The name game (2011-06)
Walker, Colin
Cactus and Succulent Journal of NSW, 27(8) (pp. 170-177)
Macaronesian memories. The succulents of the Canary Islands, Morocco and Madeira (2011-06)
Walker, Colin
Cactus and Succulent Journal of NSW, 27(8) (pp. 182-186)
What's in a name: an update on epithets used in Aloe L. (Asphodelaceae) (2011)
Smith, G.F.; Walker, Colin and Figueiredo, E.
Bradleya, 29 (pp. 179-181)
Gilbert Westacott Reynolds: his study of Aloe and a bibliography of his work (2010)
Walker, Colin
Bradleya, 28, (pp. 111-124)
Editorial: Darwin and Kew anniversaries (2009)
Walker, Colin
Bradleya, 27 (pp. 1-2)
A new name in Monsonia (2008-12)
Walker, Colin
CactusWorld, 26(4) (pp. 248-249)
Brachystelma bracteolatum Meve a rare Nigerian endemic (2008-12)
Walker, Colin C.
Asklepios, 103 (pp. 19-22)
Bradleya 25 and the Linnaean legacy (2007)
Walker, Colin C.
Bradleya, 25 (pp. 1-8)
A tale of two Arabian aloes (2005)
Walker, Colin
British Cactus & Succulent Journal, 23 (pp. 175-179)
xTavarorbea - another intergeneric hybrid stapeliad (2005)
Walker, Colin C.
Asklepios(92) (pp. 7-8)
Two succulent aroids (2004-12)
Walker, Colin
British Cactus & Succulent Journal, 22 (pp. 185-187)
A new intergeneric hybrid stapeliad (2004-11)
Walker, Colin
New Zealand Cactus & Succulent Journal, 57(4) (pp. 103-107 + cover)
James Harvey Callander and his rare publication: Cactus Culture for Amateurs (1906) (2002)
Walker, Colin
Cactus and Succulent Journal (US), 74(3) (pp. 121-126)
Introducing the Nolinaceae (2001-12)
Walker, Colin
British Cactus & Succulent Journal, 19(4) (pp. 214-221)
The botanical paintings of Mary Maud Page (2001)
Smith, Gideon F. and Walker, Colin C.
Bradleya, 19 (p 124)
Canaries and kasbahs - the succulents of the Canary Islands and Morocco - Part 2 (2000-08)
Walker, Colin C.
New Zealand Cactus & Succulent Journal, 53(3) (pp. 70-77)
Canaries and kasbahs - the succulents of the Canary Islands and Morocco (2000-05)
Walker, Colin C.
New Zealand Cactus & Succulent Journal, 53(2) (pp. 36-49)
John Medley Wood's Natal Asclepiads (2000-04)
Walker, Colin C. and Downs, Philip E.
Asklepios(79) (pp. 3-9)
Agave attenuata and some new cultivars (2000)
Walker, Colin C.
British Cactus & Succulent Journal, 18(2) (pp. 95-98)
Arabian asclepiads of Albert Deflers (1999-04)
Walker, Colin
Asklepios(76) (pp. 23-32)
A tale of dragons - the pachycaul species of Dracaena (1999)
Walker, Colin
British Cactus & Succulent Journal, 17(4) (pp. 171-177)
Senecio rowleyanus (1999)
Smith, G.F.; Walker, Colin and Condy, G.
Flowering Plants of Africa, 56 (pp. 116-120, t.2160)
A question of balance: when is a Caralluma a Caralluma and not a Caudanthera? (1997-12)
Walker, Colin
Asklepios(72) (pp. 12-13)
A.A. Bullock and his asclepiad studies (1997-12)
Walker, Colin
Asklepios(72) (pp. 20-24)
Van Rheede and the first Ceropegia (1997-08)
Walker, Colin
Asklepios(71) (pp. 26-34)
Obetia ficifolia - a pachycaul stinging nettle (1997)
Burston, Colin; Martin, Ralph and Walker, Colin
British Cactus & Succulent Journal, 15(1) (pp. 2-6)
James Donn and the succulents of 'Hortus Cantabrigiensis' (1996)
Walker, Colin C.
Bradleya, 14 (pp. 20-28)
Echeveria setosa var. deminuta (1994-09)
Walker, Colin
British Cactus & Succulent Journal, 12(3) (pp. 90-91)
Robert Brown's contributions to asclepiad study (1994-08)
Walker, Colin
Asklepios(62) (pp. 20-34, plate 1)
Frederick Scheer (1792-1868) of Kew (1994)
Walker, Colin C.
Kew Magazine, 11(2) (pp. 74-81)
Sansevierias make scents (1994)
Walker, Colin
British Cactus & Succulent Journal, 12 (p 92)
The Asclepiads of Morocco - a short commentary (1993-08)
Jonkers, Bert and Walker, Colin C.
Asklepios(59) (pp. 14-21)
Pilea peperomioides - a Chinese member of the stinging nettle family (1993)
Walker, Colin
British Cactus & Succulent Journal, 11(4) (pp. 98-99)
A note on the Carallumas of Jordan (1992)
Walker, Colin
Asklepios(55) (pp. 17-19)
The argan - multipurpose tree of Morocco (1992)
Prendergast, Hew D.V. and Walker, Colin C.
Kew Magazine, 9(2) (pp. 76-85)
Aloe dumetorum Mathew & Brandham - a dwarf Kenyan endemic (1991-06)
Walker, Colin C.
British Cactus & Succulent Journal, 9(2) (pp. 28-31)
Kleinia (Senecio) anteuphorbium (L.)Haw. - a Moroccan endemic (1991)
Walker, C. C. and Thorburn, M.
Aloe, 28(1) (pp. 18-22)
Pelargonium ceratophyllum L'Herit: the antler-leaved stork's bill (1990-09)
Walker, Colin C.
British Cactus & Succulent Journal, 8 (pp. 84-86)
Trichosacme lanata Zucc. - a woolly Mexican asclepiad (1990)
Walker, Colin
Asklepios, 51 (pp. 56-59)
Cussonia paniculata: the mountain cabbage tree (1988-12)
Walker, Colin C.
British Cactus & Succulent Journal, 6(4) (pp. 98-100)
xBrachypelia: a novel intergeneric hybrid (1988)
Walker, C. C.
Asklepios, 43 (pp. 83-86)
The euphorbias of Gran Canaria, Canary Islands (1987)
Walker, Colin C. and Thorburn, Marjorie
The Euphorbia Journal, 4 (pp. 32-47)
Pelargonium crassicaule L'Herit (1987)
Walker, C. C.
Aloe, 24(2) (pp. 32-34)
Dischidia - an obscure organism? (1987)
Walker, Colin
Asklepios, 40 (pp. 75-80)
More on Dischidia (1986)
Walker, Colin
Asklepios, 38 (pp. 11-13)
Adenia glauca: a 'lump' with an interesting life-style (1985-03)
Walker, Colin C.
British Cactus & Succulent Journal, 3(1) (pp. 18-20)
Dischidia: an introduction to asclepiad ant plants (1985)
Walker, C. C.
Asklepios, 35 (pp. 3-11)
Cremnophila nutans: A Sedum under another name? (1984)
Walker, C. C.
British Cactus & Succulent Journal, 2(4) (pp. 100-103)
Sarcostemma: leafless succulent lianas (1983)
Walker, C.C.
Asklepios, 29 (pp. 18-21)
The ciliated Orbea (1983)
Walker, C.C.
Asklepios, 27 (pp. 59-63)
Brachystelma: an introduction and checklist (1982)
Walker, C. C.
Asklepios, 25 (pp. 92-106)
A new name in Brachystelma (1981)
Walker, Colin
Asklepios, 24 (pp. 66-67)
More on Tridentea Haw (1980)
Walker, Colin
Asclepiadaceae, 20 (pp. 7-10)
Aloes – The definitive guide (2011)
Carter, S.; Lavranos, J. J.; Newton, L. E. and Walker, C. C.
ISBN : 9781842464397 | Publisher : Kew Publishing in association with the British Cactus and Succulent Society | Published : London
Beaucarnea RUSCACEAE (2018-11)
Walker, Colin
In: Eggli, Urs and Nyffeler, Reto eds. Monocotyledons. Illustrated Handbook of Succulent Plants
ISBN : 978-3-662-56484-4 | Publisher : Springer Verlag | Published : Berlin, etc.
Nolina RUSCACEAE (2018-10-08)
Walker, Colin
In: Eggli, Urs and Nyffeler, Reto eds. Monocotyledons. Illustrated Handbook of Succulent Plants
ISBN : 978-3-662-56324-3 | Publisher : Springer Verlag | Published : Berlin
Dracaena RUSCACEAE (2018-07-04)
Walker, C. C.
In: Eggli, Urs and Nyffeler, Reto eds. Monocotyledons. Illustrated Handbook of Succulent Plants (SUCCPLANTS)
Publisher : Springer Verlag
Cordyline LAXMANNIACEAE (2018-06-14)
Walker, Colin
In: Eggli, Urs and Nyffeler, Reto eds. Monocotyledons. Illustrated Handbook of Succulent Plants
ISBN : 978-3-662-56324-3 | Publisher : Springer Verlag | Published : Berlin
Laxmanniaceae (2018-06-14)
Walker, Colin
In: Eggli, Urs and Nyffeler, Reto eds. Monocotyledons. Illustrated Handbook of Succulent Plants
ISBN : 978-3-662-56324-3 | Publisher : Springer Verlag | Published : Berlin
Dasylirion (Ruscaceae) (2018-06-14)
Walker, Colin
In: Eggli, Urs and Nyffeler, Reto eds. Monocotyledons. Illustrated Handbook of Succulent Plants
ISBN : 978-3-662-56324-3 | Publisher : Springer Verlag | Published : Berlin
Foreword (2011)
Walker, Colin
In: Craib, Charles and Lavranos, John eds. The Bushman Candles (x-xi)
ISBN : 978-0-620-48776-4 | Publisher : Penrock Publications | Published : Bryanston, South Africa
Crassulaceae (Umbilicus) (2003)
Walker, Colin
In: Eggli, Urs ed. Crassulaceae. Illustrated Handbook of Succulent Plants (6) (pp. 364-367)
ISBN : 3-540-41965-9 | Publisher : Springer-Verlag | Published : Berlin
Asteraceae (Baeriopsis) (2002)
Walker, Colin
In: Eggli, Urs ed. Dicotyledons. Illustrated Handbook of Succulent Plants (p 20)
ISBN : 3-540-41966-7, 978-3-540-41966-2 | Publisher : Springer-Verlag | Published : Berlin
Bombacaceae (Adansonia, Cavanillesia, Ceiba, Pseudobombax) (2002)
Walker, Colin
In: Eggli, Urs ed. Dicotyledons. Illustrated Handbook of Succulent Plants (4) (pp. 48-52)
ISBN : 3-540-41966-7 | Publisher : Springer-Verlag | Published : Berlin
Oxalidaceae (Oxalis) (2002)
Walker, Colin
In: Eggli, Urs ed. Dicotyledons. Illustrated Handbook of Succulent Plants (pp. 333-336)
ISBN : 3-540-41966-7 | Publisher : Springer-Verlag | Published : Berlin
Urticaceae (Laportea, Obetia, Pilea) (2002)
Walker, Colin
In: Eggli, Urs ed. Dicotyledons. Illustrated Handbook of Succulent Plants (4) (pp. 447-450)
ISBN : 3-540-41966-7 | Publisher : Springer-Verlag | Published : Berlin
Urticaceae (Laportea, Obetia, Pilea) (2002)
Walker, Colin
In: Eggli, Urs ed. Zweikeimblaettrige Pflanzen (Dicotyledonen).. Sukkulenten-Lexikon (pp. 478-480)
ISBN : 3-8001-3915-4 | Publisher : Verlag Eugen Ulmer | Published : Stuttgart
Dracaenaceae (Cordyline, Dracaena) (2001)
Walker, Colin
In: Eggli, Urs ed. Monocotyledons. Illustrated Handbook of Succulent Plants (1) (pp. 258-261)
ISBN : 3-540-41692-7 | Publisher : Springer-Verlag | Published : Berlin
Nolinaceae (Beaucarnea, Calibanus, Dasylirion, Nolina) (2001)
Walker, Colin
In: Eggli, Urs ed. Monocotyledons. Illustrated Handbook of Succulent Plants (1) (pp. 286-292)
ISBN : 3-540-41692-7 | Publisher : Springer-Verlag | Published : Berlin
A history of succulent exploration in East and North-East Africa (2004)
Walker, Colin
In : Proceedings of the International Symposium: The Succulent Plants of Eastern Africa: History, Botanical Exploration and Research, (20-22 Sep 2002, Rome, Italy)

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