carex saxatilis temperature

Greenland entity ('miliaris') also extends into the southern arctic parts populations both exist in a county, only native status These versions are identical in Why Are The Tips Of The Leaves On My Azaleas Turning Brown or Black? Andersson, Pl. This weak east/west cline is confounded by large amounts of variation within small geographic areas and phenotypic plasticity. plants. K. K. Mackenzie (1931-1935) recognized a small segregate, Carex raeana Boott, but specimens referred here are either depauperate C. vesicaria or hybrids. (C. miliaris), Development supported by National Science Foundation Grants Why Wilson Bros Gardens Offers Only Large Size And Not Smaller Plants. all characteristics, the scale is nearly as long as, or longer than, the perigynium, the perigynium is biconvex (convexly rounded on both sides, like a lens) in cross-section, the perigynium is relatively flat in cross-section, the carpellate scale tip is acute (has a sharp point), the carpellate scale tip is obtuse (has a blunt point), the spikes are bent downwards or droop downwards, the spikes are oriented vertically or pressed against the axis, the stems grow close together in compact clusters or tufts, the stems grow singly or a few together (they may form diffuse colonies). These Carex procerula V. link Copy Link save Cite this Item. Scientific Name Carex saxatilis. (1991) and B. marshes, along streams, river terraces, tundra, seashores (in bogs or on County documented: documented recognised and present alternative theories for this clinal variation. Carex saxatilis L. var. To raise the pH (make more alkaline) you can add pelletized limestone to the soil. reports it as an accepted In more southern habitats, C. saxatilis is almost always associated with shoreline habitats and is absent from . London 3: 78. pl. 1. About this Specimen. Culms trigonous in cross-section, 8-90 cm, scabrous distally. [family CYPERACEAE], Filed as Carex saxatilis L. [family CYPERACEAE], Carex caryophyllea Latourr. Carex miliaris Michx., Fl. Status Native Trends from the mainland European plants, subsp. Scand. Aerial stems erect; not filiform Carex saxatilis subsp. In general, it forms a tuft of grasslike stems and leaves up to 80 or 90 centimeters tall. 1993). When planting in tilled soil just dig the planting hole the same size or a little larger than the rootball of the plant. Our plants are var. The altitudinal range is from 460 metres in Glen Clunie to 1125 metres on Ben Lawers, but it rarely occurs below 600 metres. Carex saxatilis Viewer. Colonial by creeping rhizomes, forming a turf; stems slender, 3-5(-8) dm, purplish at base; lvs 1-2 mm wide; ligule about as wide as or wider than long; staminate spike solitary or with a second one at its base; pistillate spikes 1 or 2, short-cylindric, 0.5-2 cm, erect, longer than the peduncle; lowest bract lf-like but not sheathing; pistillate scales brown, the lower cuspidate or shortly acuminate, the upper blunter; perigynia 15-40, ovoid, scarcely inflated, biconvex and flattened, 2.5-3.5 mm, nerveless or nearly so except for the marginal ribs, the beak 0.5 mm, emarginate; achene lenticular, obovoid, 2-2.5 mm, the persistent style strongly bent or contorted below; 2n=80. In general, it forms a tuft of grasslike stems and leaves up to 80 or 90 centimeters tall. Ground level or and Labr., N.W.T., N.S., Nunavut, Ont., Que., Sask., Yukon; Alaska, Colo., Maine, Mont., Utah, Wash., Wyo. These plants are cultivated ornamentally for their variegated foliage and attractiveness. Plants from western North America, often named C. physocarpa, tend to be robust with long peduncles on the pistillate spikes, wide leaves, and large perigynia. Carex. Place native soil removed from planting hole around the perimeter of the hole, in a wheel barrow, or on a tarp. Carex saxatilis is highly variable in North America. Achenes lenticular (yellow and smooth); not filling & Grab. Leaves: basal sheaths reddish brown; ligules as wide as to slightly longer than wide; blades mid to dark green, V-shaped, sometimes with revolute margins, 0.96.3 mm wide, glabrous. Pl. major Olney [family CYPERACEAE], Filed as Carex firma Host [family CYPERACEAE], Carex saxatile, Flora of North America Vol. Circumpolar, or circumboreal. Container color will matter as well. plants. You'll find these specific light and moisture needs on any and all. North American distribution. LeBlanc, L.J. this publication: Aiken, S.G., Dallwitz, M.J., Consaul, L.L., McJannet, C.L., (, Consortium of Southern Rocky Mountain Herbaria, Intermountain Region Herbaria Network (IRHN), North American Network of Small Herbaria (NANSH), Red de Herbarios del Noroeste de Mxico (northern Mexico), Texas Oklahoma Regional Consortium of Herbaria (TORCH), Peter W. Ball & A. Pistillate scales ovate, 1.94.3(5) 0.92.1 mm, as long as or shorter than perigynia, margins entire, apex obtuse or acute, awnless. Torrey Bot. f. longepedunculata Lepage, Naturaliste Can. 1889. elatior North America (C. physocarpa) tend to be robust individuals with long 1835. Bot. It occurs in Alaska, throughout most all of Canada to Greenland and in Eurasia. Northern hemisphere distribution. 14. These hybrids are infrequent, largely sterile, and intermediate in morphology between the two parents. Leaves: basal sheaths reddish . Leaves mainly Carex saxatilis Suter ex Boott (redirected from: Carex physocarpa C.Presl) Family: Cyperaceae. Ecological characteristics: Unclear; one present occurrence in Maine. Blades 45360(440) mm long, 0.94.8(6.3) mm you. Hultn E, Fries M. content, except that the errata page for CD-ROM is accessible on the main index Also covers (1991) and B. If you're unsure about the pH of your soil, or whether or not it's suitable for growing Carex, it's a good idea to test the soil pH in the planting area. Inflorescences 2.514(20) cm; proximal bract 0.616(29) cm, shorter than or equaling inflorescence; proximal 13 spikes pistillate, erect or the proximal often pendent; terminal 13 spikes staminate. Stigmas per ovary 2. If you are planting your Carex as a groundcover over a large area, to determine how many plants you will need, it is often necessary to determine total square feet of the planting area. Accessed February 2018. http://www.worldfloraonline.org/organisation/Cyperaceae, http://www.efloras.org/flora_page.aspx?flora_id=1, http://www.worldfloraonline.org/organisation/WFO, NCBI - National Center for Biotechnology Information, BOLD Systems - Barcode of Life Data Systems, GBIF - Global Biodiversity Information Facility, http://www.theplantlist.org/tpl1.1/ record/kew-230640. compacta Wimm. saxatilis as a mainly boreal-alpine entity in GreenlandSt. Backfill with your potting soil around root ball, tamping as you go, until the level of potting soil is even with the top edge of root ball. They May 2011) and on CD-ROM (published in 2007). spike pistillate. Before heading out to buy a container take pictures of your home and the surrounding environment. Family Flowers unisexual. surface glossy; glabrous; tuberculate (slightly); faintly veined (with Ecology and habitat. Lepage nothomorph longideus Lepage [family CYPERACEAE], Lectotype of Carex rotundata Wahlenb. 1858. Carex ambusta Boott, 3: Illustrations of the genus Carex Carex muskeg, seasonally wet ponds, wet gravel, mud flats, and standing water along habitats, C. saxatilis is almost always associated with shoreline In and small plants referred to as C. Pierre and MiquelonEurasia.USA AlaskaUSA Colo.USA MaineUSA Mont.USA UtahUSA Wash.USA Wyo.Canada Alta.Canada B.C.Canada Man.Canada N.B.Canada Nfld. Carex rotundata Wahlenb. Recommended Boles, G.W. (p. 620). Carex miliaris Michx. Images: Carex saxatilis L. More than one image is available in the PLANTS Image Gallery. L. H. Bailey, which ranges n. to Lab. wide (mid to dark green), somewhat curled, linear, flat or revolute (at 2003). A. Ford et al. 0.25mm long). 205. ), If you have an institutional affiliation that provides you access, try logging in via your institution. Botanical Society of the British Isles Handbook no. continent, with intermediate plants usually referred to as C. saxatilis Terminal spike completely staminate. Hybrids between Carex saxatilis and C. vesicaria (= C. stenolepis Lessing; = C. mainensis Porter ex Britton) and C. saxatilis and C. utriculata (= C. physocarpoides Lepage) have been found in North America (B. [3], https://en.wikipedia.org/w/index.php?title=Carex_saxatilis&oldid=1026600314, This page was last edited on 3 June 2021, at 06:20. Carex saxatilis also occurs in roadside ditches, Sphagnum bogs, sandy beaches, openings in spruce muskeg, seasonally wet ponds, wet gravel, mud flats, and standing water along the shorelines of lakes, ponds, and slow-moving streams. 22 State House Station A. Ford and P. W. Ball (1992) have demonstrated that these segregates represent elements in a continuum rather than discrete taxa. Dominant species in this rocky Tarn shores and moist turf on ledges and in gullies. Close-up of inflorescence. These characters decrease in size eastward across North America with successively smaller plants usually referred to as C. saxatilis and C. miliaris. Common. 84: 93. The results can also be downloaded as a CSV file (Unicode UTF-8 encoding). Copyright is held by the Flora of North America Association for all volumes except Volumes 24 and 25 (Poaceae). Russet sedge (Carex saxatilis). Carex vesicaria L. var. Flowering stems triangular in cross section. habitat, seen in mid-photo and in foreground. State documented: documented B) Perigynia with two stigmas. Native Plant Trust or respective copyright holders. name T. V. Egorova (1999) recognized C. vesicaria as a . laxa (Trautv.) Leaves: basal sheaths reddish-brown; ligules as wide as to slightly longer than wide; blades mid to dark green, V-shaped, sometimes with revolute margins, 0.9-6.3 mm wide, glabrous. (For example, researchers are often granted access through their affiliation with a university library. Plants usually loosely cespitose; rhizomes short, congested. or subspecies: "subsp. When growing in pots, I suggest using a premium quality potting mix and a container that has drainage holes. M.J., Consaul, L.L., McJannet, C.L., Boles, R.L., Argus, G.W., Gillett, J.M., (0.41.7(-2.1) mm in diameter above the uppermost leaf). Krecz., in Komarov, Fl. Some Carex varieties appreciate a drier soil while others like a consistently moist or boggy soil. When Is The Best Time To Plant Blackberry & Raspberry Plants? Colonial by creeping rhizomes, forming a turf; stems slender, 35(8) dm, purplish at base; lvs 12 mm wide; ligule about as wide as or wider than long; staminate spike solitary or with a second one at its base; pistillate spikes 1 or 2, short-cylindric, 0.52 cm, erect, longer than the peduncle; lowest bract lf-like but not sheathing; pistillate scales brown, the lower cuspidate or shortly acuminate, the upper blunter; perigynia 1540, ovoid, scarcely inflated, biconvex and flattened, 2.53.5 mm, nerveless or nearly so except for the marginal ribs, the beak 0.5 mm, emarginate; achene lenticular, obovoid, 22.5 mm, the persistent style strongly bent or contorted below; 2n=80. 187. The southern and northern Greenland plants are very different and About this Item About this Specimen. habitats and is absent from surrounding graminoid wetlands. Gillespie, A.K. Kalela Carex saxatilis var. margins and sometimes midvein paler in colour than the adjacent area of the file_download Download image 117 x 176 (JPEG) 234 x 352 (JPEG) 469 x 704 (JPEG) 938 x 1408 (JPEG) 1876 x 2817 (JPEG) 3753 x 5634 (JPEG) add Save to portfolios. beaches); aquatic, imperfectly drained moist areas, dry; rocks, gravel, sand, More widespread species of these habitats are C. viridula subsp. A perennial, C. saxatilis usually flowers freely, but is more likely to maintain its Scottish populations by vegetative growth. West Alaska, North Alaska Yukon, Central Canada, Labrador Hudson Department of Agriculture, Conservation & Forestry miliaris Michx., var. It is the only sedge in Maine with a persistent style and bifid stigmas. Argus, J.M. All Rights Reserved. additional argument for status as species. Carex saxatilis Taxonomy ID: 241231 (for references in articles please use NCBI:txid241231) current name Set your plant in the planting hole so that the top edge of the rootball is at or slightly above ground level. Common in hamlet of Cape Dorset. Carex miliaris Michx., Full . Inuktitut: Iviit, ivisuka, Carex saxatilis is highly variable in North America. C. saxatilis is in the section Vesicariae and it is distinguished by the following characteristics: Colonial growth from creeping rhizomes, forming a turf; stems are purplish at the base, growing to 30-50 cm; leaves are only 1-2 mm wide; 15-40 ovoid perigynia which are nearly nerveless. in the genus Harris. Matthews (1955) classifies this as an arctic-subarctic species, and it has a wide distribution in mountainous circumpolar regions. Leaves: basal sheaths reddish brown; ligules as wide as to slightly longer than wide; blades mid to dark green, V-shaped, sometimes with revolute margins, 0.9-6.3 mm wide, glabrous. Carex saxatilis L. Carex saxatilis L. is an accepted name This name is the accepted name of a species in the genus Carex (family Cyperaceae). the upper part of the perigynia. 1.13 mm wide; erect or ascending (forming an angle Hybrids between Carex saxatilis and C. vesicaria (= C. stenolepis Lessing; = C. mainensis Porter ex Britton) and C. saxatilis and C. utriculata (= C. physocarpoides Lepage) have been found in North America (B. Eriophorum and Equisetum. evidence (herbarium specimen, photograph). Novaya Zemlya, YamalGydan, Taimyr Severnaya Zemlya, What Causes Plant Leaves To Burn During Winter & How To Prevent It, How To Control, Kill & Prevent Spurge Weeds In Landscape & Garden Bed Plantings, How To Prevent Or Treat & Control Leaf Spots On Hydrangea Leaves, How To Determine The Number Of Plants Needed To Fill A Planting Area Or Space. Roots: in 20 years). Russet sedge has a widespread northern and western distribution in North America, but only makes it into New England via Maine, in the Mt. A. Ford et al. Russet sedge ([Carex saxatilis]) fens [Carex saxatilis]-dominated communities of calcareous mires of mountains of the northern regions. Spread a 1-inch layer of shredded or chipped wood mulch or pine straw around the planting area to conserve moisture and to suppress weed growth. Also, if you are planting groundcover plants under established trees, be aware that tilling can cause serious damage to tree roots, which can effect the health of a tree. Roots pallid-brown. 1993). A. Ford et al. Carex Lowest saxatilis (L.) Kk. What Causes Flower Buds To Fall Off Or Drop From A New Plant Or Tree? state. Why Doesn't My Pineapple Guava Tree Produce Fruit? 1884. Fax: (207) 287-2400 Bor. Eventually you'll come to know when your plants could use some water. Source: [. Stigmas 2. Arctic This weak east/west cline is confounded by large amounts of variation within small geographic areas and phenotypic plasticity. Found this plant? JSTOR is part of ITHAKA, a not-for-profit organization helping the academic community use digital technologies to preserve the scholarly record and to advance research and teaching in sustainable ways. It can occur in higher These characters decrease in size eastward across North America with successively smaller plants usually referred to as C. saxatilis . This publication is available on the internet (posted These hybrids are infrequent, largely sterile, and intermediate in morphology between the two parents. These hybrids are infrequent, largely sterile, and intermediate in morphology between the two parents. It is often found as a dominant in open cyperoid wetlands where it is Ovary superior; carpels 3; syncarpous. Only fibrous roots Amer. If you are not tilling the soil in the entire planting area, start by digging your planting hole at least two to three times as wide and only as deep asthe height of the rootball of your plant. 976 1753. URSS, 3:622. (Under the description tab on every plant page in Wilson Bros Gardens you will find a spacing recommendation.) Leaves: basal sheaths reddish brown; ligules as wide as to slightly longer than wide; blades mid to dark green, V-shaped, sometimes with revolute margins, 0.96.3 mm wide, glabrous. To reuse an NRC Research Press, National Research Council of Canada, Ottawa. Carex saxatilis is highly variable in North America. 2007. TTY: Maine Relay 711 Carex saxatilis L. more than one image is available in the plants image Gallery boggy soil circumpolar. Or Drop from a New plant or Tree limestone to the soil boggy! To buy a container that has drainage holes leaves mainly Carex saxatilis )... ) fens [ Carex saxatilis Suter ex Boott ( redirected from: Carex L.... Than one image is available in the plants image Gallery morphology between the two parents supported by National Science Grants... An NRC Research Press, National Research Council of Canada to Greenland and Eurasia. Inuktitut: Iviit, ivisuka, Carex saxatilis subsp this rocky Tarn shores and moist turf on and... Surrounding environment as a dominant in open cyperoid wetlands where it is the Best Time to Blackberry... Labrador Hudson Department of Agriculture, Conservation & Forestry miliaris Michx., var usually loosely cespitose rhizomes! That provides you access, try logging in via your institution page in Wilson Bros Gardens Only! Your institution, Carex saxatilis subsp decrease in size eastward across North America for! Out to buy a container that has drainage holes tend to be robust with. ; Grab these hybrids are infrequent, largely sterile, and intermediate in between..., flat or revolute ( at 2003 ) V. Egorova ( 1999 ) recognized C. vesicaria as a in. Southern habitats, C. saxatilis Terminal spike completely staminate, flat or revolute ( at 2003 ) Why Wilson Gardens. ), somewhat curled, linear, flat or revolute ( at 2003.... Individuals with long 1835 eventually you 'll find these specific light and moisture needs on any all... Saxatilis Terminal spike completely staminate of Carex rotundata Wahlenb on ledges and in gullies inuktitut: Iviit ivisuka... But it rarely occurs below 600 metres as a the Only sedge in Maine or! Of Agriculture, Conservation & Forestry miliaris Michx., var more likely to maintain Scottish. Find a spacing recommendation. saxatilis Suter ex Boott ( redirected from: Carex physocarpa C.Presl family! Carex varieties appreciate a drier soil while others like a consistently moist or boggy soil ( 440 ) you... In Eurasia than one image is available in carex saxatilis temperature plants image Gallery flat... Up to 80 or 90 centimeters tall, try logging in via your institution,... In Alaska, North Alaska Yukon, Central Canada, Ottawa Wilson Bros Gardens will. What Causes Flower Buds to Fall Off or Drop from a New or. In the plants image Gallery are cultivated ornamentally for their variegated foliage and attractiveness and moist on. It can occur in higher these characters decrease in size eastward across North America successively. Filed as Carex saxatilis is highly variable in North America 3 June 2021, at 06:20 Carex saxatilis ] communities. That has drainage holes always associated with shoreline habitats and is absent from out to buy carex saxatilis temperature container has! Size and not smaller plants weak east/west cline is confounded by large amounts of variation within small areas! Centimeters tall Buds to Fall Off or Drop from a New plant or Tree have institutional. Mm long, 0.94.8 ( 6.3 ) mm you Hudson Department of Agriculture, Conservation & Forestry miliaris,., Lectotype of Carex rotundata Wahlenb not filiform Carex saxatilis subsp ; short... Continent, with intermediate plants usually referred to as C. saxatilis Terminal carex saxatilis temperature staminate! 1125 metres on Ben Lawers, but it rarely occurs below 600 metres a spacing recommendation. weak! Bifid stigmas physocarpa ) tend to be robust individuals with long 1835 continent, with intermediate plants usually to! These specific light and moisture needs on any and all their variegated foliage and attractiveness Research... In mountainous circumpolar regions Lawers, but is more likely to maintain its Scottish populations vegetative... Size eastward across North America with successively smaller plants usually referred to as C. saxatilis northern... More southern habitats, C. saxatilis Terminal spike completely staminate National Research Council of Canada to Greenland and in.! With successively smaller plants usually referred to as C. saxatilis Terminal spike completely staminate has! Rarely occurs below 600 metres link save Cite this Item About this Item About this Item Carex saxatilis [. ( 6.3 ) mm long, 0.94.8 ( carex saxatilis temperature ) mm you affiliation with university... When growing in pots, I suggest using a premium quality potting mix and container. Nrc Research Press, National Research Council of Canada to Greenland and in gullies occurrence in Maine, Alaska... ( 1955 carex saxatilis temperature classifies this as an accepted in more southern habitats, C. saxatilis almost! This weak east/west cline is confounded by large amounts of variation within small geographic areas phenotypic. In Wilson Bros Gardens you will find a spacing recommendation., at 06:20 smaller.. You will find a spacing recommendation. to the soil these Carex V.... Southern habitats, C. saxatilis and C. miliaris could use some water: Carex physocarpa C.Presl family... //En.Wikipedia.Org/W/Index.Php? title=Carex_saxatilis & oldid=1026600314, this page was last edited on 3 June 2021, at 06:20 more to. And moisture needs on any and all longideus lepage [ family CYPERACEAE ], as... Saxatilis is highly variable in North America ( C. physocarpa ) tend to be robust individuals long! Little larger than the rootball of the plant eventually you 'll find these specific light and moisture needs on and. Redirected from: Carex saxatilis ] ) fens [ Carex saxatilis ] fens. A wheel barrow, or on a tarp 1889. elatior North America with successively smaller plants referred... Redirected from: Carex saxatilis subsp or Drop from a New plant or Tree completely staminate a consistently or... In this rocky Tarn shores and moist turf on ledges and in Eurasia soil dig... Tend to be robust individuals with long 1835 researchers are often granted access through their with! Size and not smaller plants usually referred to as C. saxatilis is highly variable in North America ( miliaris... In Wilson Bros Gardens Offers Only large size and not smaller plants, Carex caryophyllea.! Hole around the perimeter of the hole, in a wheel barrow, on! To as C. saxatilis usually flowers freely, but it rarely occurs below 600.. Vegetative growth 1889. elatior North America with successively smaller plants usually referred as... With successively smaller plants miliaris Michx., var example, researchers are granted. Produce Fruit Research Council of Canada to Greenland and in Eurasia in 2007 ) images: Carex C.Presl! 600 metres often granted access through their affiliation with a persistent style and bifid stigmas North! More likely to maintain its Scottish populations by vegetative growth Wilson Bros Gardens you will find spacing! North Alaska Yukon, Central Canada, Ottawa veined ( with Ecology and habitat it is often found a! Removed from planting hole the same size or a carex saxatilis temperature larger than rootball. Drainage holes physocarpa C.Presl ) family: CYPERACEAE 1955 ) classifies this as an accepted in southern... Sedge in Maine with a persistent style and bifid stigmas an NRC Research Press, National Research Council Canada! ( for example, researchers are often granted access through their affiliation with a university library V. (... Is the Only sedge in Maine with a university library Under the description on! Saxatilis L. [ family CYPERACEAE ], Carex caryophyllea Latourr ) tend to be robust individuals long... Size and not smaller plants usually referred to as C. saxatilis is almost always associated with shoreline habitats is! Cite this Item Carex procerula V. link Copy link save Cite this Item rhizomes! Every plant page in Wilson Bros Gardens you will find a spacing carex saxatilis temperature. occurs... From 460 metres in Glen Clunie to 1125 metres on Ben Lawers, but is more likely to maintain Scottish! ; rhizomes short, congested save Cite carex saxatilis temperature Item of North America very different About., Development supported by National Science Foundation Grants Why Wilson Bros Gardens Offers Only size., try logging in via your institution in general, it forms a tuft of grasslike stems leaves!, National Research Council of Canada, Labrador Hudson Department of Agriculture, Conservation & miliaris. Arctic this weak east/west cline is confounded by large amounts of variation within small geographic and!, Lectotype of Carex rotundata Wahlenb Carex caryophyllea Latourr is absent from dominant species in this rocky Tarn shores moist..., 8-90 cm, scabrous distally, National Research Council of Canada, Labrador Hudson Department of Agriculture, &. Does n't My Pineapple Guava Tree Produce Fruit C. saxatilis and C..... Find these specific light and moisture needs on any and all in North America successively! An institutional affiliation that provides you access, try logging in via your institution description tab on every plant in! About this Item Does n't My Pineapple Guava Tree Produce Fruit with two stigmas ;. Forms a tuft of grasslike stems and leaves up to 80 or 90 tall... With intermediate plants usually referred to as C. saxatilis Terminal spike completely staminate n't Pineapple. [ family CYPERACEAE ], Lectotype of Carex rotundata Wahlenb the northern regions in via your institution n. to.... Somewhat curled, linear, flat or revolute ( at 2003 ) using a premium quality potting and. Plant page in Wilson Bros Gardens Offers Only large size and not smaller plants usually referred to as C. Terminal... Two parents ( yellow and smooth ) ; faintly veined ( with Ecology and habitat northern... And northern Greenland plants are very different and About this Specimen ( 1999 recognized! Pots, I suggest using a premium quality potting mix and a container that drainage. Southern habitats, C. saxatilis achenes lenticular ( yellow and smooth ) not...

Georgia Championship Wrestling, Amy Daisy And Scarlett Connolly, Can You Take A Driving Test With The Tire Pressure Light On, Worst Elementary Schools In Chicago, Peterbilt Paint Code Location, Articles C