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.
William Taylor Marshall: His Contributions to Succulent Plant Study and a Full Bibliography of His Published Work (2023-12)
Walker, Colin C. and Schultz, David M.
Haseltonia, 30(1) (pp. 27-48)
Aloe pendens Forsskal - a cliff-dwelling species from the Yemen (2023-10)
Walker, Colin
Haworthiad, 37(3) (pp. 72-75)
Ceropegia armandii : a remarkable dimorphic Madagascan endemic (2023-09-01)
Walker, Colin
Cactus & Succulent Review(38) (pp. 15-18)
Aloe whitcombei Lavranos - a unique and highly localised Omani endemic (2023-06)
Walker, Colin
Haworthiad, 37(2) (pp. 46-48)
Mangaves (2023-06)
Walker, Colin
Cactus & Succulent Review(37) (pp. 5-10)
Succulents contained: Euphorbia confinalis subsp. confinalis (2023-06)
Walker, Colin
CactusWorld, 41(2) (pp. 154-154)
Stapelia hirsuta (2023-03)
Walker, Colin
Cactus & Succulent Review(36) (pp. 15-17)
Agave nizandensis - a unique dwarf Mexican species (2023-03)
Walker, Colin
CactusWorld, 41(1) (pp. 51-55)
Succulents contained: Haemanthus albiflos (2023-03)
Walker, Colin
CactusWorld, 41(1) (pp. 34-34)
Tropical East African aloes: conservation status, uses and threats (2023-03)
Walker, Colin
CactusWorld, 41(1) (pp. 75-76)
New literature. Cristini, Marco. The genus Aeonium (2023-03)
Walker, Colin
CactusWorld, 41(1) (pp. 81-82)
Aloe fibrosa - a shrubby East African species (2023-02)
Walker, Colin
Haworthiad, 37(1) (pp. 14-16)
Sansevierias: an introduction (2023-01)
Walker, Colin
Cactus and Succulent Journal of NSW, 33(3 & 4) (pp. 33-43)
Two contrasting stapelias (2023)
Walker, Colin
New Zealand Cactus & Succulent Journal, 76(1) (pp. 23-26)
Orbea hardyi: A creeping stapeliad endemic to northern South Africa (2023)
Walker, Colin
Cactus and Succulent review(39) (pp. 4-6)
Euphorbia evolution and taxonomy (2022-12)
Walker, Colin
CactusWorld, 40(4) (pp. 299-300)
Madagascan euphorbias (2022-12)
Walker, Colin
CactusWorld, 40(4) (pp. 300-301)
Euphorbia susannae is endangered in the wild (2022-12)
Walker, Colin
CactusWorld, 40(4) (pp. 301-301)
The history and flowering of Agave xleopoldii (2022-12)
Walker, Colin
Cactus & Succulent Review(35) (pp. 9-12)
Succulents contained: Sansevieria subspicata (2022-12)
Walker, Colin
CactusWorld, 40(4) (pp. 262-262)
An introduction to Mexican Sedums (2022-11)
Walker, Colin
New Zealand Cactus & Succulent Journal, 75(2) (pp. 28-34)
Aloe jucunda - a highly localised, critically endangered Somalian endemic (2022-10)
Walker, Colin
Haworthiad, 36(2) (pp. 61-63)
Rhipsalis pilocarpa. A rare and localised Brazilian endemic (2022-09)
Walker, Colin
Cactus and Succulent Review, 34 (pp. 8-10)
Stapelia leenderztiae - a uniquely large, tubular-flowered species (2022-09)
Walker, Colin
CactusWorld, 40(3) (pp. 216-218)
Aloe palmiformis - an Angolan endemic (2022-09)
Walker, Colin
CactusWorld, 40(3) (pp. 175-178)
Chichimecactus: a new genus (2022-09)
Walker, Colin
CactusWorld, 40(3) (pp. 227-227)
Succulents contained: Monanthes polyphylla subsp. polyphylla (2022-09)
Walker, Colin
CactusWorld, 40(3) (pp. 212-212)
Echeveria cuspidata (2022-06)
Walker, Colin
Cactus & Succulent Review(33) (pp. 10-12)
Desmidorchis survives as a conserved name (2022-06)
Walker, Colin
CactusWorld, 40(2) (pp. 147-148)
Two recently described spotted-leaved, endemic Kenyan Aloes (2022-06)
Walker, Colin
Haworthiad, 36(2) (pp. 31-33)
Succulents contained: Eulychnia acida (2022-06)
Walker, Colin
CactusWorld, 40(2) (pp. 104-104)
Palmer's Culture des Cactées - a rare cactus book (2022-05)
Walker, Colin
Bradleya, 40 (pp. 231-248)
Succulents contained: Agave montana (2022-03-17)
Walker, Colin
CactusWorld, 40(1) (pp. 71-71)
Cotyledon - a small, highly diverse and complex African genus (2022-03)
Walker, Colin
CactusWorld, 40(1) (pp. 6-15)
A couple of cotyledons (2022-02)
Walker, Colin
New Zealand Cactus & Succulent Journal, 75(1) (pp. 10-14)
Sansevieria pinguicula - the 'walking' Sansevieria (2021-12)
Walker, Colin
Cactus & Succulent Review(31) (pp. 17-20)
Succulents contained: Sedum lucidum (2021-12)
Walker, Colin
CactusWorld, 39(4) (pp. 300-300)
Aristaloe aristata: a unique, monotypic species (2021-10)
Walker, Colin
Haworthiad, 35(3) (pp. 76-79)
Aloe jacksonii updated (2021-10)
Walker, Colin
Haworthiad, 35 (p 59)
Three South African Crassulas and the botanical art of Baron von Jacquin (2021-09)
Walker, Colin
Cactus & Succulent Review, 30 (pp. 31-39)
Stapelia divaricata Masson - the rarest and most localised species of Stapelia (2021-09)
Walker, Colin
CactusWorld, 39(3) (pp. 247-249)
Atlantic Aeoniums (2021-08)
Walker, Colin
New Zealand Cactus & Succulent Journal, 74(2) (pp. 20-34)
Kalanchoe tomentosa (2021-06)
Walker, Colin
Cactus and Succulent Review(29) (p 38)
State of the world's plants and fungi (2021-06)
Walker, Colin
CactusWorld, 39(2) (pp. 161-162)
Dragon trees updated (2021-06)
Walker, Colin
CactusWorld, 39(2) (pp. 165-165)
A survey of succulents of the mallow family (Malvaceae) (2021-06)
Walker, Colin
CactusWorld, 39(2) (pp. 135-148)
Heidi Hartmann and a life with mesembs (2021-06)
Walker, Colin
CactusWorld, 39 (pp. 164-165)
Aloe squarrosa Baker - a unique and highly localised Socotran endemic (2021-06)
Walker, Colin
Haworthiad, 35(2) (pp. 50-53)
Aloiampelos ciliaris var. ciliaris. Asphodelaceae: Alooideae (2021-06)
Smith, G. F.; Figueiredo, E.; Klopper, R. R.; Crouch, N. R.; Walker, C. C. and Condy, Gillian
Flowering Plants of Africa, 67 (pp. 18-30)
Kalanchoe beharensis. Crassulaceae: Kalanchooideae (2021-06)
Smith, G. F.; Figueiredo, E.; Walker, C. C. and Condy, Gillian
Flowering Plants of Africa, 67 (pp. 50-59)
The succulents of Portmeirion Pottery (2021-03)
Walker, Colin
Cactus & Succulent Review(28) (pp. 47-53)
Agave evolution and taxonomy (2021-03)
Walker, Colin
CactusWorld, 39(1) (pp. 73-74)
A review of the Euphorbia schinzii complex in Southern Africa (2021-03)
Walker, Colin
CactusWorld, 39(1) (pp. 74-75)
Halting plant extinction webinar (November 2020) (2021-03)
Walker, Colin
CactusWorld, 39(1) (pp. 79-80)
Pollination biology of Stenocereus queretaroensis and the importance of bat pollination services (2021-03)
Walker, Colin
CactusWorld, 39(1)
Two succulent mallows: Ceiba speciosa and Pseudobombax ellipticum (2021)
Walker, Colin
New Zealand Cactus & Succulent Journal, 74(1) (pp. 16-19)
Aloe kedongensis - a shrubby Kenyan endemic (2021)
Walker, Colin
Haworthiad, 35(1) (pp. 20-24)
Aloe tewoldei - a rare, cliff-dwelling Ethiopian endemic (2021)
Walker, Colin
Haworthiad, 35(1) (pp. 4-5)
Cactus & succulent books for children (2021)
Walker, Colin C. and Schultz, David
Cactus and Succulent Journal (US), 93(2) (pp. 197-204)
Aloidendron dichotomum. Der Urtyp der Baumaloe. The archetypal tree aloe (2021)
Walker, Colin
Avonia, 39(3) (pp. 210-219)
Aloe forbesii - a small Socotran endemic (2020-12)
Walker, Colin C.
CactusWorld, 38(4) (pp. 325-327)
Agave pablocarrilloi (2020-08)
Walker, Colin
New Zealand Cactus & Succulent Journal, 73(2) (pp. 13-15)
Aloidendron barberae: the largest tree aloe (2020-06)
Walker, Colin C.
CactusWorld, 38(2) (pp. 141-144)
Literature review. McCoy, Tom. The Aloes of Arabia (2020-06)
Walker, Colin
CactusWorld, 38(2) (pp. 154-155)
Literature review. Stutchbury, Ralph. Baobab [Book review] (2020-06)
Walker, Colin
CactusWorld, 38(2) (pp. 155-156)
Aloe cremnophila - a cliff-dwelling Somali endemic (2020-02-01)
Walker, Colin
Haworthiad, 34(1) (pp. 3-5)
Aloidendron barberae: the world's largest tree aloe observed in New Zealand and South Africa (2020-02)
Walker, Colin
New Zealand Cactus & Succulent Journal, 73(1) (pp. 17-21)
Filiferous agaves (2020)
Walker, Colin
CactusWorld, 38(1) (pp. 41-48)
Stapelia engleriana the "iceberg" species from Southern Africa (2020)
Walker, Colin
Asklepios, 126 (pp. 15-16)
Aloe huntleyana - a rare cliff-dwelling Namibian endemic (2020)
Walker, Colin
Haworthiad, 34(3) (pp. 78-81)
Contrasting growth habits of some arid-loving southern African aloes (2020)
Crook, Ivor; Pearcy, Les and Walker, Colin C.
Haworthiad, 34(3) (pp. 65-68)
The life and times of Gordon Rowley (1921-2019) (2019-12)
Walker, Colin
CactusWorld, 37(4) (pp. 257-262)
Two spectacularly spiny alluaudias (2019-11)
Walker, Colin
New Zealand Cactus & Succulent Journal, 72(3) (pp. 5-8)
Aloe spectabilis - a splendid South African species (2019-10)
Walker, Colin
Haworthiad, 33(3) (pp. 58-59)
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)
Aloe erensii, Aloe jucunda and a new cultivar (2019)
Walker, Colin C. and Mace, Suzanne
CactusWorld, 37(1) (pp. 13-19)
Caputia tomentosa (2019)
Walker, Colin; Smith, G.F.; Crouch, N.R. and Condy, Gillian
Flowering Plants of Africa, 66 (pp. 168-178)
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
Malvaceae (2023-05-03)
Walker, Colin
In: Eggli, Urs and Nyffeler, Reto eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants (pp. 801-806)
ISBN : 978-3-030-93491-0 | Publisher : Springer, Cham
Adansonia MALVACEAE (2023-05-03)
Walker, C. C. and Eggli, U.
In: Eggli, Urs and Nyffeler, Reto eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants (pp. 807-820)
ISBN : 978-3-030-93491-0 | Publisher : Springer, Cham
Brachychiton MALVACEAE (2023-05-03)
Forster, P. I.; Guymer, G. P. and Walker, C. C.
In: Eggli, Urs and Nyffeler, Reto eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants (pp. 821-825)
Publisher : Springer, Cham
Cavanillesia MALVACEAE (2023-05-03)
Walker, Colin
In: Eggli, Urs and Nyffeler, Reto eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants (pp. 827-833)
ISBN : 978-3-030-93491-0 | Publisher : Springer, Cham
Ceiba MALVACEAE (2023-05-03)
Walker, Colin
In: Eggli, Urs and Nyffeler, Reto eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants (pp. 835-841)
ISBN : 978-3-030-93491-0 | Publisher : Springer, Cham
Megistostegium MALVACEAE (2023-05-03)
Walker, Colin
In: Eggli, Urs and Nyffeler, Reto eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants (pp. 834-845)
ISBN : 978-3-030-93491-0 | Publisher : Springer Nature | Published : Switzerland
Sterculia MALVACEAE (2023-05-03)
Forster, P. I.; Guymer, G. P.; Van Jaarsveld, E. J. and Walker, C. C.
In: Eggli, Urs and Nyffeler, Reto eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants (pp. 853-858)
ISBN : 978-3-030-93492-7 | Publisher : Springer, Cham
Urticaceae (2023-05-03)
Walker, C. C. and Eggli, U.
In: Eggli, Urs and Nyffeler, Reto eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants (pp. 1071-1074)
ISBN : 978-3-030-93492-7 | Publisher : Springer, Cham
Obetia URTICACEAE (2023-05-03)
Walker, Colin
In: Eggli, Urs and Nyffeler, Reto eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants (pp. 1077-1078)
ISBN : 978-3-030-93491-0 | Publisher : Springer, Cham
Pilea URTICACEAE (2023-05-03)
Walker, Colin
In: Eggli, Urs and Nyffeler, Reto eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants (pp. 1079-1084)
ISBN : 978-3-030-93491-0 | Publisher : Springer, Cham
Pseudobombax Malvaceae (2023)
Walker, Colin
In: Eggli, Urs and Nyffeler, Reto eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants (pp. 847-852)
ISBN : 978-3-030-93491-0 | Publisher : Springer Nature | Published : Switzerland
Laportea Urticaceae (2023)
Walker, Colin
In: Eggli, Urs and Nyffeler, Reto eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants (pp. 1075-1076)
ISBN : 978-3-030-93491-0 | Publisher : Springer Nature | Published : Switzerland
Ceiba MALVACEAE (2022-06-30)
Walker, Colin
In: Eggli, U. and Nyffeler, R. eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants
Publisher : Springer | Published : Cham
Adansonia MALVACEAE (2022-06-29)
Walker, Colin
In: Eggli, U. and Nyffeler, R. eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants (pp. 807-820)
Publisher : Springer | Published : Cham
Obetia URTICACEAE (2022-06-25)
Walker, C.C.
In: Eggli, U. and Nyffeler, R. eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants (SUCCPLANTS)
ISBN : 978-3-030-85239-9 / 978-3-030-85239-9 | Publisher : Springer, Cham | Published : Switzerland
Pilea URTICACEAE (2022-06-25)
Walker, Colin
In: Eggli, U. and Nyffeler, R. eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants
Publisher : Springer | Published : Cham
Brachychiton MALVACEAE (2022-06-25)
Walker, Colin; Forster, P.I.; Guymer, G.P. and van Jaarsveld, E.J.
In: Eggli, U. and Nyffeler, R. eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants
Publisher : Springer | Published : Cham
Malvaceae (2022-06-16)
Walker, Colin
In: Eggli, U. and Nyffeler, R. eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants (2nd ed.)
Publisher : Springer | Published : Cham
Laportea URTICACEAE (2022-06-09)
Walker, C. C.
In: Eggli, U. and Nyffeler, R. eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants
Publisher : Springer | Published : Cham
Megistostegium MALVACEAE (2022-05-12)
Walker, Colin
In: Eggli, U. and Nyffeler, R. eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants
Publisher : Springer | Published : Cham
Pseudobombax MALVACEAE (2022-05-06)
Walker, Colin
In: Eggli, U. and Nyffeler, R. eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants
Publisher : Springer | Published : Cham
Cavanillesia Malvaceae (2022-05-05)
Walker, C. C.
In: Eggli, U. and Nyffeler, R. eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants(2nd. ed.)
Publisher : Springer | Published : Cham
Sterculia MALVACEAE (2022-04-26)
Forster, P.I.; Guymer, G.P.; Van Jaarsveld, E.J. and Walker, C.C.
In: Eggli, Urs and Nyffeler, Reto eds. Dicotyledons: Rosids. Illustrated Handbook of Succulent Plants, 2nd ed
ISBN : 978-3-030-85239-9 | Publisher : Springer | Published : Cham
Urticaceae (2022-02-05)
Walker, C.C. and Eggli, U.
In: Eggli, U. and Nyffeler, R. eds. Dicotyledons: Rosids (2nd ed). Illustrated Handbook of Succulent Plants
ISBN : 978-3-030-93491-0 / 978-3-030-85239-9 | Publisher : Springer International Publishing | Published : Cham
Beaucarnea Ruscaceae (2020)
Walker, Colin
In: Eggli, Urs and Nyffeler, Reto eds. Monocotyledons. Illustrated Handbook of Succulent Plants (2nd editio) (pp. 1319-1328)
ISBN : 978-3-662-56484-4 | Publisher : Springer Reference | Published : Berlin
Dasylirion Ruscaceae (2020)
Walker, Colin
In: Eggli, Urs and Nyffeler, Reto eds. Monocotyledons. Illustrated Handbook of Succulent Plants (2nd ed.) (pp. 1329-1335)
ISBN : 978-3-662-56484-4 | Publisher : Springer Reference | Published : Berlin
Dracaena Ruscaceae (2020)
Walker, Colin
In: Eggli, Urs and Nyffeler, Reto eds. Monocotyledons. Illustrated Handbook of Succulent Plants (pp. 1337-1344)
ISBN : 978-3-662-56484-4 | Publisher : Springer Reference | Published : Berlin
Nolina Ruscaceae (2020)
Walker, Colin
In: Eggli, Urs and Nyffeler, Reto eds. Monocotyledons. Illustrated Handbook of Succulent Plants (2nd ed.) (pp. 1345-1351)
ISBN : 978-3-662-56484-4 | Publisher : Springer Reference | Published : Berlin
Laxmanniaceae (2020)
Walker, Colin
In: Eggli, Urs and Nyffeler, Reto eds. Monocotyledons. Illustrated Handbook of Succulent Plants (2nd ed.) (pp. 1293-1294)
ISBN : 978-3-662-56484-4 | Publisher : Springer Reference | Published : Berlin
Cordyline Laxmanniaceae (2020)
Walker, Colin
In: Eggli, Urs and Nyffeler, Reto eds. Monocotyledons. Illustrated Handbook of Succulent Plants (2nd ed.) (pp. 1295-1296)
ISBN : 978-3-662-56484-4 | Publisher : Springer Reference | Published : Berlin
Foreword (2019)
Walker, Colin
In: Smith, Gideon F.; Figueiredo, Estrela and van Wyk, Abraham E. eds. Kalanchoe (Crassulaceae) in Southern Africa (ix-x)
ISBN : 978-0-12-814007-9 | Publisher : Academic Press (Elsevier) | 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)