Pascal Pittorino / Lemon tree (Citrus limon) covered in snow, Var, Provence, France, February.

Larry Minden / Desert Tortoise (Gopherus agassizii) emerging from burrow beneath Mohave Desertrue (Thamnosma montana), Mojave Desert, California

Nigel Cattlin / Glasshouse mealy bug (Pseudococcus viburni) honeydew from infestation on Lemon (Citrus limon) fruit, cultivated in conservatory.

Nigel Cattlin / Glasshouse mealy bug (Pseudococcus viburni) infestation on Lemon (Citrus limon) fruit, cultivated in conservatory.

Nigel Cattlin / Californian red scale insect (Aonidiella aurantii) scales on Orange (Citrus sinensis) leaf, zonal chlorosis present. Native to China. Sicily, Italy. October.

Nigel Cattlin / Californian red scale (Aonidiella aurantii) infestation on Lemon (Citrus limon) wood. Native to China. Sicily, Italy. October.

Nigel Cattlin / Californian red scale (Aonidiella aurantii) infestation on Lemon (Citrus limon) wood. Native to China. Sicily, Italy. October.

Nigel Cattlin / Californian red scale (Aonidiella aurantii) infestation on Lemon (Citrus limon) stem. Native to China. Sicily, Italy. October.

Heather Angel / Sichuan pepper (Zanthoxylum bungeanum) branch with fruit.Sichuan, China. July.

Heather Angel / Honey bee (Apis mellifera) extending proboscis to nectar on Common rue (Ruta graveolens). Green aphid (Aphidoidea) beneath flower. Surrey, England, UK. July.

Heather Angel / Parasitic wasp (Gasteruption assectator) nectaring on Common rue (Ruta graveolens). Surrey, England, UK. July.

Heather Angel / Blowfly (Calliphora sp) nectaring on Common rue (Ruta graveolens). Surrey, England, UK. July.

Heather Angel / Common rue (Ruta graveolens) flower. Cultivated in herb garden, Surrey, England, UK. Native to Balkan Peninsula.

Heather Angel / Seville orange (Citrus aurantium) flower. Cultivated in glasshouse, Surrey, England, UK. Focus stacked. Sequence 1/2.

Heather Angel / Seville orange (Citrus aurantium) flower fluorescing in UV light, colour attractive to pollinators. Cultivated in glasshouse, Surrey, England, UK. Focus stacked. Sequence 2/2.

Heather Angel / Common rue (Ruta graveolens) flower in visible light, nectar at base of petals. Stamens flip up sequentially with one still folded over the receptacle. Surrey, England, UK. Native to Balkan Peninsula....

Heather Angel / Common rue (Ruta graveolens) flower in UV light, pollen and nectar at base of petals fluorescing. Insect pollinators are able to see position of rewards on offer. Surrey, England, UK. Native to Balkan...

Heather Angel / Marmalade hoverfly (Episyrphus balteatus) feeds Meadow rue (Thalictrum sp) pollen. Body covered with pollen which will be transferred to next flower visited. Russian Caucasus. June.

Heather Angel / Chinese meadow-rue (Thalictrum delavayi) flowers. Male phase below with stigmas hanging below immature stigmas, female phase above after stamens have fallen. Sha Chong He River Valley, near Danba, Sic...

Edwin Giesbers / Lemon (Citrus limon), fruit growing on tree. Cyprus. April.

Philippe Clement / Japanese bitter-orange (Poncirus trifoliata / Citrus trifoliata) citrus fruit in tree, October

Jiri Lochman / Plant biodiversity on stabilized coastal dunes with Shark Bay Rose (Diplolaena grandiflora) and Sandhill Wattle (Acacia ligulata) in the foreground, Shark Bay UNESCO Natural World Heritage Site, Weste...

Jiri Lochman / Shark bay rose (Diplolaena grandiflora) , Shark Bay UNESCO Natural World Heritage Site, Western Australia.

Jiri Lochman / Shark Bay rose (Diplolaena grandiflora), Shark Bay UNESCO Natural World Heritage Site, Western Australia.

Jiri Lochman / Shark bay rose (Diplolaena grandiflora), Shark Bay UNESCO Natural World Heritage Site, Western Australia.

Jiri Lochman / Shark bay rose (Diplolaena grandiflora), Shark Bay UNESCO Natural World Heritage Site, Western Australia.

Hanne & Jens Eriksen / Rue (Haplophyllum tuberculatum) close-up of flowers, Oman, March

Nick Upton / Lesser meadow rue (Thalictrum minus) flowering among Purple scabious (Knautia purpurea) on Piva plateau, near Trsa, Montenegro, July.

Nick Upton / Oranges (Citrus sinensis) fruits ripening, Argolis, Peloponnese, Greece, August 2013.

Nick Upton / Unripe and ripe Oranges (Citrus sinensis) hanging on a tree in an orange grove, Argolis, Peloponnese, Greece, August 2013.

Alex Hyde / Wall rue spleenwort (Asplenium ruta-muraria) growing out of a stone wall. Derbyshire, UK. August.

Pascal Pittorino / Lemon tree (Citrus limon) covered in snow, Var, Provence, France, February.

Juan Manuel Borrero / Orange (Citrus sinensis) tree flowers. Cultivated plant.

Martin Gabriel / Caucasian burning bush (Dictamnus caucasicus) flowering, Northern Armenia, May.

Martin Gabriel / Caucasian burning bush (Dictamnus caucasicus) flowering, Northern Armenia, May.

Vladimir Medvedev / Amur cork tree (Phellodendron amurense) branches with berries, Amur Region, Russia.

Vladimir Medvedev / Amur cork tree (Phellodendron amurense) trunk, Amur Region, Russia.

Rod Williams / Goat's Rue (Galega officinalis) Greenwich Peninsula Eco Park July

Cheryl-Samantha Owen / Oranges (Citrus sp) in orchard on Suikerbossie farm, Koue Bokkeveld / Cedarberg region, Western Cape, South Africa.

Cheryl-Samantha Owen / Oranges (Citrus sp) in orchard on Suikerbossie farm, Koue Bokkeveld / Cedarberg region, Western Cape, South Africa.

Cheryl-Samantha Owen / Orange (Citrus sp) orchard irrigation on Suikerbossie farm, Koue Bokkeveld / Cedarberg region, Western Cape, South Africa. The water comes from rainwater, mountain run-off and the Twee River, which fl...

Cheryl-Samantha Owen / Orange (Citrus sp) orchard irrigation on Suikerbossie farm, Koue Bokkeveld / Cedarberg region, Western Cape, South Africa. The water comes from rainwater, mountain run-off and the Twee River, which fl...

Cheryl-Samantha Owen / Farm workers harvesting Oranges (Citrus sp) on Suikerbossie farm, Koue Bokkeveld / Cedarberg region, South Africa. February 2014.

Cheryl-Samantha Owen / Trailers of harvested Oranges (Citrus sp) on Suikerbossie farm, Koue Bokkeveld / Cedarberg region, South Africa. February 2014.

Chris Mattison / Butterwort (Pinguicula gigantea) leaves, insectivorous plants, cultivated specimen.

Paul Harcourt Davies / Goat's Rue (Galega officinalis) in flower, Podere Montecucco, Orvieto, Umbria, Italy, July.

Dong Lei / Low angle shot of flowers (Thalictrum sp) Basoncuo National Park, Tibet, China, Asia, July.

Adrian Davies / Mould (Penicillin italicum) growing on a Satsuma (Citrus unshi)

Adrian Davies / Mould (Penicillin italicum) growing on a Satsuma (Citrus unshiu)

Paul Harcourt Davies / Great meadow rue (Thalictrum alpinum) in flower, Monte Spinale, alpine zone, Madonna di Campiglio, Brenta Dolomites, Italy, July 2010

Paul Harcourt Davies / Great meadow rue (Thalictrum alpinum) in flower, Monte Spinale, alpine zone, Madonna di Campiglio, Brenta Dolomites, Italy, July 2010

Alex Hyde / Wall Rue Spleenwort (Asplenium ruta-muraria) growing out of a fissure in a limestone cliff. Lathkill Dale NNR, Peak District National Park, UK. June.

MYN / Clay Bolt / Rue anemone (Thalictrum thalictroides) Dacusville, Pickens County, South Carolina, USA, April. meetyourneighbours.net project

MYN / Clay Bolt / Rue anemone (Thalictrum thalictroides) Dacusville, Pickens County, South Carolina, USA, April. meetyourneighbours.net project

Florian Möllers / Wall rue spleenwort (Asplenium ruta-muraria) growing on a wall in a cemetery, Berlin, Germany, October

Florian Möllers / Wall rue spleenwort (Asplenium ruta-muraria) growing on a wall in a cemetery, Berlin, Germany, October

Robert Thompson / Aerial view of Rue point and the south lighthouse, Rathlin Island, County Antrim, Northern Ireland, UK, September 2009

Philippe Clement / Common rue / Herb-of-grace (Ruta graveolens) flowers, Belgium

Philippe Clement / Common rue / Herb-of-grace (Ruta graveolens) in flower, Belgium

Wild Wonders of Europe / Giesbers / French meadow-rue (Thalictrum aquilegifolium) flowers, Liechtenstein, June 2009

Jason Smalley / Wall rue spleenwort on rock {Asplenium ruta muraria}, Yorkshire, UK

Jose B. Ruiz / Fringed rue flower {Ruta chalepensis} Alicante, Spain

Rod Williams / Rue du Bain-aux-Plantes, in the old city (Petite France) Strasbourg, France

Pascal Tordeux / Goat's Rue / French Lilac / Italian Fitch / Professor Weed (Galega officinalis). French Alps, July.

Loic Poidevin / Diosma (Diosma hirsuta) in flower, Cotes d'Armor, Brittany, France. April.

Adrian Davies / Satsuma (Citrus sp.) with mould (Penicillium sp.), in visible light at top and fluorescing in UV light below.

Paul Harcourt Davies / Ruby-tailed / Cuckoo wasp (Chrysis comparata) feeding on Rue flower (Ruta graveolens). Podere Montecucco, Orvieto, Italy. June.

Dave Watts / Mexican orange blossom (Choisya ternata) with dead branches and leaves caused by extreme heat and over 3 months of drought, Natural Park of Haut Languedoc, Herault , Southern France. August, 2022.

Dave Watts / Mexican orange blossom (Choisya ternata) with dead branches and leaves caused by extreme heat and over 3 months of drought, Natural Park of Haut Languedoc, Herault , Southern France. August, 2022.

Philippe Clement / Chinese prickly-ash (Zanthoxylum simulans) close-up of spines on tree trunk. Native to China and Taiwan.

Paul Harcourt Davies / Shining meadow rue (Thalictrum lucidum) in flower in wet meadow, Piediluco, Umbria, Italy. May.

Paul Harcourt Davies / Shining meadow rue (Thalictrum lucidum) in flower in wet meadow, Piediluco, Umbria, Italy. May.

Paul Harcourt Davies / Dittany (Dictamnus albus) in flower in woodland, Orvieto, Umbria, Italy. May.

Paul Harcourt Davies / Goat's-rue (Galega officinalis) in flower, Mount Pitigliano, Tuscany, Italy. June.

Nigel Cattlin / Normal, mono-embryonic Orange (Citrus sinensis) seedlings with normal single development of root and shoot.

Nigel Cattlin / Two polyembryonic Orange (Citrus sinensis) seedlings showing bifurcation, a malformation, with each seed developing two plants.

Linda Pitkin / Goat's-rue (Galega officinalis) in flower, Nutfield Marsh Nature Reserve, Surrey, England. July.

Linda Pitkin / Wildflower meadow with fowering Goat's-rue (Galega officinalis), Nutfield Marsh Nature Reserve, Surrey, England. July.

Linda Pitkin / White Goat's-rue (Galega officinalis) in flower, Nutfield Marsh nature reserve, Surrey, England. July.

Linda Pitkin / White Goat's-rue (Galega officinalis) in flower, Nutfield Marsh nature reserve, Surrey, England. July.

Linda Pitkin / Goat's-rue (Galega officinalis) in flower, Nutfield Marsh nature reserve, Surrey, England. July.

Linda Pitkin / Goat's-rue (Galega officinalis) in flower, Nutfield Marsh nature reserve, Surrey, England. July.

Paul Harcourt Davies / Caterpillar of Common yellow swallowtail butterfly (Papilio machaon), dark morph, feeding on Common rue (Ruta graveolens) as a foodplant, Umbria, Italy. October.

Paul Harcourt Davies / Caterpillar of Common yellow swallowtail butterfly (Papilio machaon), dark morph, on Common rue (Ruta graveolens) as a foodplant, Umbria, Italy. October.

Paul Harcourt Davies / Caterpillar of Common yellow swallowtail butterfly (Papilio machaon) on Common rue (Ruta graveolens) as a foodplant, Umbria, Italy. October.

Paul Harcourt Davies / Buff-tailed bumblebee (Bombus terrestris) visiting flower of Dittany (Dictamnus albus), Umbria, Italy. May.

Paul Harcourt Davies / Dittany (Dictamnus albus) in flower, in woodland, Umbria Italy. May.

Paul Harcourt Davies / Lemon (Citrus limon) flower, Umbria, Italy. June.

Paul Harcourt Davies / Lemon (Citrus limon) flower, buds and fruit, Umbria, Italy. June.

Paul Harcourt Davies / Great meadow-rue (Thalictrum aquilegifolium) flower head, Umbria, Italy. May.

Nigel Cattlin / Stem end rot (Lasiodiplodia theobromae) on stored lemon (Citrus limon) fruit crop.

Nigel Cattlin / False codling moth (Thaumatotibia leucotreta) caterpillar on Orange (Citrus sinensis) fruit, South Africa.

Nigel Cattlin / Severe marginal chlorosis to the leaves of a mature Lemon (Citrus limon) tree caused by calcium deficiency, South Africa.

Nigel Cattlin / Citrus bud mite (Aceria sheldoni) damage 'Hand of Buddha' distortion to a Lemon (Citrus limon) fruit, South Africa.

Nigel Cattlin / Citrus leaf miner (Phyllocnistis citrella) leaf mines made by larvae in a Pummelo (Citrus maxima) leaf, Thailand, South East Asia.

Will Watson / Rustyback Fern (Ceterach officinarum) and Wall-rue (Asplenium ruta-muraria) growing on sandstone wall, Herefordshire, England, December, focus stacked.