member plant family family comprising genera known species order word derives latin ancient greek originally plant identity certain occur wide range shapes sizes live habitats subject drought live extremely dry environments found places earth adaptations conserve water meaning parts adapted store water unlike stem vital process takes place species lost true leaves retaining spines highly modified leaves defending spines help prevent water loss reducing air flow close providing shade absence leaves enlarged stems carry native americas ranging south parts western canada north grows africa sri_lanka spines produced specialized structures called kind highly reduced branch identifying feature spines rise flowers usually tubular short growing seasons long able react quickly rainfall helped extensive relatively shallow root system quickly absorb water reaching ground surface stems allows expand contract easily quick water absorption rain followed long drought periods like plants employ special mechanism called acid carbon dioxide enters plant water escapes place day time instead occurs night plant stores carbon dioxide takes acid retaining daylight returns takes place cooler humid night hours water loss significantly reduced smaller globe shaped stems combining highest possible volume water storage lowest possible surface area water loss tallest free standing maximum recorded height smallest diameter maturity fully grown said able absorb gallons imp gal water species differ significantly appearance family plants genus resemble trees shrubs growing persistent leaves older bark covered stems identify spite appearance adaptations water conservation considered close ancestral species evolved tropical regions grow forest plants grow trees stems typically flattened leaf like appearance fewer spines known christmas thanksgiving genus variety uses species ornamental plants grown fodder forage food particularly fruit product insect lives morphology species fall groups core subfamily subfamily members groups easily recognizable stems major organs absent small leaves flowers lie deeply sunken stem flower parts grow highly specialized short shoots extremely short produce spines normal shoots flowers remaining fall genera different means description frequently exceptions species resemble tropical forest trees mature woody stems covered bark long lasting leaves provide main means flowers superior points attachment produce leaves species small globe shaped bodies prominent leaves growth habit wide variety growth habits difficult divide clear simple categories tree like meaning typically single woody trunk topped branches genus branches covered leaves species genus recognized branches typically like bare leaves bark covered spines larger tree sized branches larger specimens described stems coming ground branches low smaller described consist erect cylinder shaped stems branch clear division trunk branches boundary forms tree like forms difficult define smaller younger specimens example older larger specimens tree like cases columns horizontal vertical stems growing ground intervals stems smaller described consist shorter ball shaped stems solitary stems form clusters create large stems cluster share common root different appearance tropical regions grow forest stems typically flattened leaf like appearance fewer spines climbing large specimen reported meters long root distant stem species hang downwards forming dense grow trees high ground stems stem characteristic feature majority belonging largest subfamily stem typically meaning adapted store water surface stem smooth species covered kinds usually called vary small prominent like shapes genus like leaves species stem shape prominence ribs depends water stem storing mass water ribs invisible swollen stem short water stems shrink ribs visible stems shade green bluish brownish green stems contain able carry small structures open close allow passage gases stems visibly structures unique variable typically appear areas stems spines emerge flowers produced genus believed similar ancestor occur leaves angle leaf stalk stem borne raised areas stem leaf bases highly specialized condensed shoots branches normal shoot bearing leaves flowers separated lengths stem close form single structure circular elongated oval shape separated parts parts visibly connected way groove stem appear entirely separate nearer stem produces flowers spines hairs appearance distinct color yellow brown produce new spines flowers years inactive results relatively fixed number spines flowers produced ends stems growing forming new genus close ancestor remain active longer case leaves great majority visible leaves takes place stems flattened species exceptions occur groups species like normal trees shrubs numerous leaves group subfamily visible leaves long lasting species produced growing season lost species small genus relies leaves structure leaves varies somewhat groups species normal leaves flattened blade leaves appear consist visible leaves usually small leaves long half species studied long function leaves role production plant defining suggested spines spines distinguished spines modified leaves modified branches produce spines noted spines present leaves clearly evolved complete spines young possibly particularly true tree living ground living lack spines mature spines useful identification vary greatly species number color size shape spines produced similar distinct kinds spines straight slightly curved described hair like like needle like like depending length thickness flattened spines hooked spines central spines hooked outer spines straight addition normal length spines members subfamily relatively short spines called barbed length easily shed enter skin difficult remove causing long lasting roots ground living fine roots spread base plant varying distances close surface genera considerably larger greater volume body aid larger climbing roots produced stems come contact medium flowers like spines flowers variable typically surrounded material derived stem tissue forming structure called tissue derived continues forming composite tube called floral tube strictly speaking base floral origin outside tubular structure produce wool spines typically tube small scale like gradually change like like structures clearly differentiated called produce floral tubes wool spines completely devoid external structures unlike flowers flowers borne clusters flowers usually single style branch end stigma usually arise inner surface upper floral tube produced distinct series specific areas inside floral tube flower usually symmetrical symmetrical species flower colors range white yellow red adaptations water conservation adaptations promote efficient water use surviving hot dry environments ancestors modern adapted periods intermittent drought small number species tribes adapted life tropical forests water conservation important leaves spines absence visible leaves striking features close ancestral species evolved long lasting leaves species species long lasting leaves leaves key issue retaining water ratio surface area volume water loss proportional surface area water present proportional volume structures high surface area volume ratio thin leaves necessarily lose water higher rate structures low area volume ratio stems spines modified leaves present true leaves showing evolution spines preceded loss leaves spines high surface area volume ratio maturity contain little water composed fibers dead cells spines provide protection camouflage species assist water conservation ways trap air near surface creating layer reduces provide shade temperature surface reducing water loss sufficiently moist air present fog early morning mist spines moisture ground absorbed roots stems majority stem plants stem main organ store water water form total mass stem shapes vary considerably cylindrical shape spherical shape produce low surface area volume ratio reducing water loss heating effects sunlight stems allow stem shrink periods drought swell fills water periods availability mature said able absorb gallons imp gal water outer layer stem usually tough cuticle reinforced layers reduce water loss layers responsible grayish bluish stem color stems adaptations allow conduct absence leaves discussed roots roots spread widely penetrate short distance soil case young tall root system diameter deep form new roots quickly rain falls drought concentration root cells relatively high adaptations enable absorb water rapidly periods brief light rainfall reportedly significant water hours little rainfall fully days stem acts main organ storing water addition large times length ground body case species grows places world northern chile requires plants carbon dioxide gas lose water like types reduce water loss way carry normal plants use mechanism daylight hours continually drawn air present spaces inside leaves converted compound containing carbon products access air internal spaces plant controlled able open close need continuous supply means open water continuously lost plants mechanism lose water taken roots way problem temperatures rise captures starts capture oxygen instead reducing efficiency acid mechanism adopted avoid problems mechanism open night temperatures water loss lowest enters plant captured form organic stored inside cells remain closed day uses stored uses water efficiently price limiting carbon fixed atmosphere available growth cycling efficient system open day plants mechanism night plant short water close mechanism store produced use later cycling present species studying ratio incorporated plant signature possible taken night daytime approach species investigated exhibit degree cycling suggesting ability present ancestor leaves claimed mechanism restricted stems recent studies highly unlikely significant carbon occurs stem species described having carry stem february clear stem based evolved core separately known evolved times carry stems undergone adaptations early evolutionary history ancestors modern group species developed stems began delay developing bark sufficient adaptations appear little stems stems needed develop structures similar normally found leaves immediately outer layer developed cells walls offering mechanical support air spaces needed cells allow carbon dioxide center stem developed plant tissue relatively cells containing arranged layer layer occurs taxonomy classification naming classifying difficult controversial discovered science difficulties began placed knew genera published starting point modern botanical nomenclature relegated genus word derived latin ancient greek plant later divided genera placed newly created family early 20th century came feel confused meaning genus family genus vienna botanical congress rejected instead declared type genus family conserve leading unusual situation family longer contains genus named difficulties continued partly giving plants scientific names relies type specimens ultimately want know particular plant example able compare type specimen permanently attached type specimens normally prepared compression drying stored act definitive references difficult preserve way evolved resist drying bodies easily difficulty given names result provisions international code nomenclature algae fungi plants names plants ignored particular said named renamed species names attached specimen according ensured left trail chaos probably centuries classification decided set working party called produce consensus classifications level genera system basis subsequent classifications detailed treatments published 21st century divided family genera species arranged number tribes classification family recognizes largest divided tribes subfamily genus features considered closest ancestors plants trees shrubs leaves stems smoothly round cross section having systems normal mechanism acid advanced feature water subfamily genera included subfamily leaves young lost later stems usually divided distinct joints pads plants vary size small species rising subfamily genus species form low growing features primitive plants leaves acid wholly absent subfamily tribes largest subfamily including typical members highly variable habit varying tree like leaves normally absent reduced leaves produced young plants stems usually divided segments tribes contain climbing forms different appearance stems flattened divided segments molecular phylogenetic studies supported supported tribes genera level study found genera subfamily sampled research classification currently remains uncertain likely change phylogeny evolution phylogeny study suggested genus basal confirmed earlier suggestions include descendants common ancestor consensus study shown recent study fewer genes species found divided unable resolve members core clade accepted relationships shown robust date differ geographical distribution exception clade found gulf_of_mexico caribbean_sea clade occurs south species clade lack key features stem present remaining like non stems begin form bark early plants life lack structures control admission air plant control contrast including species clade typically delay forming bark stems giving stem potential major organ highly specialized species exception thought slightly shrubs small trees leaves carried lived tropical areas experienced periodic drought clade good model early appeared similar trees growing nearby evolved strategies conserve water present members families order strategies included able respond rapidly periods rain keeping low water efficiently achieved tightly controlling opening like species today early ancestors able switch normal mechanism carbon dioxide continuously cycling closed carbon dioxide produced stored later use clade marks beginnings evolutionary switch stems organs stems formation bark takes place later normal trees core steady increase stem accompanied multiple losses leaves complete evolutionary question present unanswered switch stems occurred core case lost separately case evolved understanding evolution core clade difficult february phylogenetic relationships uncertain related current classifications study found high proportion genera descendants single common ancestor example genera subfamily sampled research found tribes recognized classification comprises single genus remaining shown study detailed discussion phylogeny classification evolutionary history known fossils exist throw light evolutionary history geographical distribution offers evidence relatively recent spread parts plants south_america mainly southern regions north_america suggests family evolved ancient continent split south_america africa occurred early cretaceous million years ago precisely split evolved clear older sources suggest early origin million years ago late cretaceous recent molecular studies suggest younger origin late early periods million years ago based phylogeny earliest group clade originated central_america northern south_america stems evolved later southern south_america moved northwards core strongly stems estimated evolved million years ago possible evolution uplifting central million years ago associated increasing varying current species diversity thought arisen million years late plants south_africa madagascar genus americas appear time coincided global expansion arid environments distribution inhabit diverse regions coastal plains high mountain areas exception native americas range extends british_columbia alberta western canada number centers diversity exist adapted drought main centers mexico southwestern united_states southwestern found peru chile argentina eastern brazil away tree living climbing necessarily different centers diversity require environments mainly found coastal mountains atlantic forests southeastern brazil center diversity subfamily forested regions central_america climbing diverse exception native americas found tropical africa madagascar sri_lanka theory spread carried seeds digestive tracts migratory birds seeds adapted bird distribution old world populations regarded distinct subspecies supporting idea spread recent alternative theory species initially crossed atlantic european ships trading south_america africa birds spread widely species outside americas having introduced people especially australia hawaii mediterranean region australia species particularly introduced 19th century use natural agricultural fences attempt establish industry rapidly major problem controlled biological agents particularly potential species australia continues leading declared april reproductive ecology flowers insects birds bats known wind self occurs species example flowers species open need attract led evolution defined groups floral traits including rewards associated attraction specific group animals bees common bee considered evolve day flying butterflies nocturnal associated different butterfly flowers usually brightly colored opening day flowers white pale color opening evening night example particular species lays eggs developing seeds later consume flowers funnel shaped white deep pink long open night significant species showing typical syndrome flowers colors red end spectrum flower shape symmetrical lower lip bends downwards produce large amounts relatively low sugar content species flowers correspond closely syndrome genera include bat relatively uncommon flowering plants quarter genera known bats unusually high proportion exceeded families genera growing areas likely bat bats able travel considerable distances effective plants growing widely separated syndrome associated bats includes tendency flowers open evening night bats active features include relatively dull color white green symmetrical shape tubular smell described production large sugar rich example bat species fruits produced flowers vary considerably dry contain large number seeds colorful sweet fruits associated seed dispersal birds seeds pass digestive systems deposited fruit falls ground eaten animals giant reported distribute seeds ants appear disperse seeds genera drier fruits fur mammals moved wind uses early history march controversy precise dates humans entered areas new world commonly found archaeological site chile dated years ago suggesting encountered early evidence use includes cave paintings brazil seeds found ancient waste mexico peru dates estimated years ago hunter likely collected fruits wild brought camps known cultivated variety purposes empire lasting 14th 16th century complex system capital 15th century mexico_city explanation origin includes word referring fruit coat arms mexico shows eagle holding snake image center myth founding symbolically linked red fruits human hearts fruit offering human hearts sun god ensured sun moving europeans encountered arrived new world late 15th century west_indies relatively genera found common genus possibly seen europeans species present english collections end 16th century according source called later shortened early 18th century purely ornamental species edible fruit continued arrive europe able species described larger fruit spain portugal indicative early use europe food plant known indian long important source food original species thought come central mexico obscure indigenous people southern north_america developed distributed range varieties including forms species hybrids fruit pads eaten spanish cultivated forms significantly industry mexico said worth million indian probably present caribbean spanish arrived soon brought europe spread rapidly mediterranean area naturally introduced early assumed native area outside americas indian important commercial crop sicily algeria north african countries fruits eaten generally flower particularly species consumed fruit edible word usually considered taken spanish applied range fruit particularly fruit long important indigenous peoples northwestern mexico southwestern united_states including preserved boiling produce drying produce alcoholic drink fruits species important food sources similar parts north_america cultivated fruit tropical southern areas provides widely grown asia dragon fruit providing edible fruit include species bodies eaten anderson reported prepared eaten like potatoes agents number species shown contain agents chemical compounds cause changes mood perception effects brain species long history use indigenous peoples americas north_america south_america contain native northern mexico southern texas individual stems high diameter found wide large stem usually ground concentrated portion stem ground center stem contains growing point sunken experienced collectors remove thin slice plant leaving growing point intact allowing plant evidence indicates use years ago dried buttons presumed site texas dated perceived means spirit world attempts roman catholic church suppress use spanish conquest largely unsuccessful middle 20th century widely indigenous peoples far north canada formally native ecuador peru different appearance tall stems high diameter branch base giving plant tree like appearance archaeological evidence use appears date years ago carvings objects showing church authorities spanish attempted suppress use failed shown christian element common anderson attributes belief holds keys heaven effects allow users reach heaven earth continues effects spiritual healing purposes combined agents tobacco species including contain ornamental plants cultivated ornamental plants time brought new world early 1800s enthusiasts europe large collections including alongside rare plants sold high prices suppliers employed collectors obtain plants wild addition growing late 1800s collectors turned popular disappearing cultivation grown particularly regions cultivation outdoors northern parts europe north_america kept grown ground grown tolerant dry atmosphere placed outside summer gardens kept cover winter drought resistant hybrids thanksgiving christmas easter widely cultivated planted outdoors regions suitable climates concern water conservation arid regions led promotion gardens requiring example california sponsored publication book plants landscapes summer dry climates group drought resistant plants recommended dry landscape uses uses human food fodder animals usually burning spines addition use agents employed medicine practice species way spread americas naturally occur regions grow india red produced scale insect lives species long peoples central north_america demand fell rapidly european manufacturers began produce synthetic middle 19th century commercial production increased following rise demand natural construction materials living fences employed woody parts buildings furniture frames houses built people mexico use parts fine spines hairs source fiber filling weaving conservation included flora cites lists species necessarily threatened extinction trade closely controlled control exercised making international trade specimens illegal permits issued exports exceptions allowed artificially propagated plants species included restrictive appendix endangered species moved countries scientific purposes accompanied export import permits main threats wild development grazing collection development takes forms construction dam near mexico caused destruction large natural habitat urban development highways destroyed habitats parts mexico new_mexico arizona including conversion land agriculture affected populations mexico dry plains cultivation chile valley slopes planted grazing areas introduced animals goats caused damage populations plants examples cited anderson generally effect peru collection sale greatly affected species example type locality near mexico virtually plants dug sale europe illegal collecting wild continues pose threat conservation conservation involves preserving habits enforcement legal protection creation specially protected areas national parks reserves examples protected areas united_states include texas california arizona latin american examples include mexico chile conservation aims preserve plants seeds outside natural habitats intention later botanical gardens play important role conservation example seeds kept long term storage desert botanical garden arizona cultivation popularity means books devoted cultivation naturally occur wide range habitats grown countries different climates precisely conditions species normally grows usually practical broad distinction need different conditions best grown separately section primarily concerned cultivation containers protection greenhouse home cultivation outside ground climates permit cultivation cultivation christmas thanksgiving cultivation hybrids growing medium purpose growing medium provide support store water oxygen dissolved minerals feed plant case general agreement open medium high air content important grown containers recommendations achieved vary greatly says asked describe perfect growing medium different answers suggests mixture parts commercial growing medium clay coarse addition soil general recommendation organic based material rest supported sources use organic material rejected altogether says want soil low free recommends coarse sand basis growing medium semi desert need careful general advice hard frequency required depends grown nature growing medium original habitat brown says lost application water reason dormant winter season need water sources water withheld winter november march issue water necessary use hard water regular recommended avoid build general advice given growing season allowed dry thorough water meter help determining soil dry light temperature semi desert exposed high light levels wild need subjected higher light levels temperatures greenhouse summer allowing temperature rise recommended minimum winter temperature required depends species involved mixed collection minimum temperature suggested cold sensitive genera particularly high fully frost hardy kept dry survives temperatures cultivation flower better exposed period cold propagation propagated seed seed early year produces benefit longer growing period seed moist growing medium kept covered environment days avoid drying wet growing medium cause seeds temperature range suggested soil temperatures promote best root growth low light levels sufficient semi desert need higher light levels produce strong growth needed conditions greenhouse higher temperatures strong sunlight reproduction makes use parts plant grow roots produce pads joints detached cut produce removed stem relatively new growth recommended cut surfaces allowed dry period days weeks forms cut surface place appropriate growing medium temperature species difficult grow cultivation grow independently free forms white yellow red bodies forms abnormal growth forms host plant stock choose grows strongly cultivation compatible plant propagated makes cuts stock joins binding unite kinds flat stock similar smaller inserted stock commercially huge numbers produced annually example korea million plants propagated value million million plants propagated diseases range attack cultivation feed include living stems roots scale insects generally found stems said pest red spider small occur large numbers constructing fine web badly marking kill particularly attack flowers resistant biological controls available roots eaten larvae flies fungus eat fungi bacteria attack particularly plants gain entry wound cause rotting accompanied red violet mold caused species cause similar rotting limited value diseases found including virus appear cause limited visible symptoms pale green spots mosaic effects streaks patches paler color species virus shown reduce growth particularly roots dry treatments virus diseases
Cactus