Calamagrostis (reed grass or smallweedTim Newbury ) is a genus of flowering plants in the grass family Poaceae, with about 260 speciesGrassBase - The Online World Grass Flora that occur mainly in temperate regions of the globe. Towards equatorial latitudes, species of Calamagrostis generally occur at higher elevations. These tufted perennials usually have hairless narrow leaves. The ligules are usually blunt. The inflorescence forms a panicle. Some may be reed-like.
The plants may be rhizomatous (underground stems with shoots), stoloniferous (with runners), or caespitose (growing in tufts or clumps). The bisexual spikelets have a single floret and generally they are purple or purple-brown. The spikelets are clustered into inflorescences, which usually develop in early- to mid-summer on long culms ( = stems).
Many species of Calamagrostis are morphologically similar, but they generally occur in distinct habitats, and they have unique geographical distributions. Given the subtle distinctions between many closely related taxa, there are several species complexes that could benefit from additional systematic study. Even the generic boundaries of the genus are controversial. For example, species in the genus Deyeuxia (named after French chemist Nicolas Deyeux), distributed largely in the southern hemisphere are morphologically very similar to species of Calamagrostis. It may be appropriate to recognize all of these species in a single genus, but this will require detailed scientific study of DNA of species from around the world.
Some Calamagrostis can be very decorative, and are widely cultivated largely in northern temperate zones. The species Calamagrostis brachytricha and the cultivar Calamagrostis × acutiflora 'Karl Foerster' are recipients of the Royal Horticultural Society's Award of Garden Merit.
The word "Calamagrostis" is derived from the Greek word kalamos (reed) and agrostis (a kind of grass).
Species Calamagrostis contains the following recognised species:
Calamagrostis abnormis (Hook.f.) U.Shukla Calamagrostis acuminata (Vickery) Govaerts Calamagrostis × acutiflora (Schrad.) DC. Calamagrostis affinis (M.Gray) Govaerts Calamagrostis ajanensis Kharkev. & Prob. Calamagrostis alajica Litv. Calamagrostis alba (J.Presl) Steud. Calamagrostis albiflora Vaniot Calamagrostis altaica Tzvelev Calamagrostis amoena (Pilg.) Pilg. Calamagrostis ampliflora Tovar Calamagrostis × andrejewii Litv. Calamagrostis angustifolia Kom. Calamagrostis anthoxanthoides (Munro) Regel Calamagrostis appressa (Vickery) Govaerts Calamagrostis archboldii Hitchc. Calamagrostis arundinacea (L.) Roth Calamagrostis atjehensis Ohwi Calamagrostis aurea (Munro) Hack. ex Sodiro Calamagrostis australis (Moritzi) Buse Calamagrostis austrodensa Govaerts Calamagrostis austroscaberula Govaerts Calamagrostis autumnalis Koidz. Calamagrostis avenoides (Hook.f.) Cockayne Calamagrostis × badzhalensis Prob. Calamagrostis baicalensis (Litv.) Steph. ex Komarov Calamagrostis balkharica P.A.Smirn. Calamagrostis benthamiana (Vickery) Govaerts Calamagrostis × bihariensis Simonk. Calamagrostis bogotensis (Pilg.) Pilg. Calamagrostis bolanderi Thurb. Calamagrostis boliviensis Hack. Calamagrostis borii Tzvelev Calamagrostis boyacensis Swallen & Garc.-Barr. Calamagrostis brachyathera (Stapf) Govaerts Calamagrostis brassii Hitchc. Calamagrostis breviaristata (Wedd.) Pilg. Calamagrostis brevifolia (J.Presl) Steud. Calamagrostis breweri Thurb. Calamagrostis cabrerae Parodi Calamagrostis cainii Hitchc. Calamagrostis calderillensis Pilg. Calamagrostis canadensis (Michx.) P.Beauv. Calamagrostis canescens (Weber) Roth Calamagrostis carchiensis Laegaard Calamagrostis carinata (Vickery) Govaerts Calamagrostis caucasica Trin. Calamagrostis cephalantha Pilg. Calamagrostis chalybaea (Laest.) Fr. Calamagrostis chaseae Luces Calamagrostis chilensis Phil. Calamagrostis chrysantha (J.Presl) Steud. Calamagrostis chrysophylla (Phil.) Govaerts Calamagrostis cleefii Escalona Calamagrostis clipeata Vaniot Calamagrostis coahuilensis P.M.Peterson, Soreng & Valde's-Reyna Calamagrostis coarctata Eaton Calamagrostis conferta (Keng) P.C.Kuo & S.L.Lu Calamagrostis × conwentzii Ulbr. Calamagrostis cordechii Govaerts Calamagrostis crassiuscula (Vickery) Govaerts Calamagrostis crispa (Rugolo & Villav.) Govaerts Calamagrostis cryptolopha (Wedd.) Hitchc. Calamagrostis curta (Wedd.) Hitchc. Calamagrostis curtoides (Rugolo & Villav.) Govaerts Calamagrostis curvula (Wedd.) Pilg. Calamagrostis cuzcoensis Tovar Calamagrostis × czerepanovii Husseinov Calamagrostis debilis Hook.f. Calamagrostis decipiens (R.Br.) Govaerts Calamagrostis decora Hook.f. Calamagrostis densiflora (J.Presl) Steud. Calamagrostis deschampsiiformis C.E.Hubb. Calamagrostis deschampsioides Trin. Calamagrostis deserticola (Phil.) Phil. Calamagrostis diemii (Rúgolo) Soreng Calamagrostis diffusa (Keng) Keng f. Calamagrostis distantifolia Luchnik Calamagrostis divaricata P.M.Peterson & Soreng Calamagrostis divergens Swallen Calamagrostis dmitrievae Tzvelev Calamagrostis drummondii (Steud.) Govaerts Calamagrostis effusiflora (Rendle) P.C.Kuo & S.L.Lu ex J.L.Yang Calamagrostis elatior (Griseb.) A.Camus Calamagrostis eminens (J.Presl) Steud. Calamagrostis emodensis Griseb. Calamagrostis epigejos (L.) Roth Calamagrostis erectifolia Hitchc. Calamagrostis eriantha (Kunth) Steud. Calamagrostis expansa (Munro ex Hillebr.) Hitchc. Calamagrostis fauriei Hack. Calamagrostis fibrovaginata Laegaard Calamagrostis fiebrigii Pilg. Calamagrostis filifolia Merr. Calamagrostis filipes (Keng) P.C.Kuo & S.L.Lu ex J.L.Yang Calamagrostis flaccida Keng f. Calamagrostis foliosa Kearney Calamagrostis frigida (Benth.) Maiden & Betche Calamagrostis fulgida Laegaard Calamagrostis fulva (Griseb.) Kuntze Calamagrostis fuscata (J.Presl) Steud. Calamagrostis gayana (Steud.) Soreng Calamagrostis gigas Takeda Calamagrostis glacialis (Wedd.) Hitchc. Calamagrostis griffithii (Bor) G.Singh Calamagrostis guamanensis Escalona Calamagrostis guatemalensis Hitchc. Calamagrostis gunniana (Nees) Reeder Calamagrostis hackelii Lillo ex Stuck. Calamagrostis hakonensis Franch. & Sav. Calamagrostis × hartmaniana Fr. Calamagrostis × haussknechtiana Torges Calamagrostis hedbergii Melderis Calamagrostis henryi (Rendle) P.C.Kuo & S.L.Lu ex J.L.Yang Calamagrostis heterophylla (Wedd.) Pilg. Calamagrostis hieronymi Hack. Calamagrostis hillebrandii (Munro ex Hillebr.) C.L.Hitchc. Calamagrostis hirta (Sodiro ex Mille) Laegaard Calamagrostis holciformis Jaub. & Spach Calamagrostis holmii Lange Calamagrostis howellii Vasey Calamagrostis hupehensis (Rendle) Chase Calamagrostis imbricata (Vickery) Govaerts Calamagrostis inaequalis (Vickery) Govaerts Calamagrostis inexpansa A.Gray Calamagrostis insperata Swallen Calamagrostis intermedia (J.Presl) Steud. Calamagrostis involuta Swallen Calamagrostis jamesonii Steud. Calamagrostis kalarica Tzvelev Calamagrostis kengii T.F.Wang Calamagrostis killipii Swallen Calamagrostis koelerioides Vasey Calamagrostis kokonorica Keng ex Tzvelev Calamagrostis korotkyi Litv. Calamagrostis korshinskyi Litv. Calamagrostis × kotulae Zapal. Calamagrostis × kuznetzovii Tzvelev Calamagrostis lahulensis G.Singh Calamagrostis lapponica (Wahlenb.) Hartm. Calamagrostis lawrencei (Vickery) Govaerts Calamagrostis leiophylla (Wedd.) Hitchc. Calamagrostis leonardii Chase Calamagrostis levipes (Keng) P.C.Kuo & S.L.Lu ex J.L.Yang Calamagrostis licentiana Hand.-Mazz. Calamagrostis ligulata (Kunth) Hitchc. Calamagrostis linifolia Govaerts Calamagrostis llanganatensis Laegaard Calamagrostis longiseta Hack. Calamagrostis macbridei Tovar Calamagrostis macilenta (Griseb.) Litv. Calamagrostis macrophylla (Pilg.) Pilg. Calamagrostis malamalensis Hack. ex Stuck. Calamagrostis mandoniana (Wedd.) Pilg. Calamagrostis matsumurae Maxim. Calamagrostis mckiei (Vickery) Govaerts Calamagrostis menhoferi Govaerts Calamagrostis mesathera (Vickery) Govaerts Calamagrostis microseta (Vickery) Govaerts Calamagrostis minarovii Hüseyin Calamagrostis minima (Pilg.) Tovar Calamagrostis minor (Benth.) J.M.Black Calamagrostis mollis Pilg. Calamagrostis montanensis (Scribn.) Scribn. ex Vasey Calamagrostis moupinensis Franch. Calamagrostis muiriana B.L.Wilson & Sami Gray Calamagrostis mulleri Luces Calamagrostis munroi Boiss. Calamagrostis nagarum (Bor) G.Singh Calamagrostis nardifolia (Griseb.) Hack. ex Stuck. Calamagrostis neesii Steud. Calamagrostis neocontracta Govaerts Calamagrostis niitakayamensis Honda Calamagrostis ningxiaensis D.Z.Ma & J.N.Li Calamagrostis nitidula Pilg. Calamagrostis nivicola (Hook.f.) Hand.-Mazz. Calamagrostis nudiflora (Vickery) Govaerts Calamagrostis nutkaensis (J.Presl) Steud. Calamagrostis obtusata Trin. Calamagrostis ophitidis (Howell) Nygren Calamagrostis orbignyana (Wedd.) Pilg. Calamagrostis orizabae (Rupr. ex E.Fourn.) Beal Calamagrostis ovata (J.Presl) Steud. Calamagrostis × paradoxa Lipsky Calamagrostis parsana (Bor) M.Dogan Calamagrostis parviseta (Vickery) Reeder Calamagrostis patagonica (Speg.) Makloskie Calamagrostis pavlovii (Roshev.) Roshev. Calamagrostis perplexa Scribn. Calamagrostis petelotii (Hitchc.) Govaerts Calamagrostis pickeringii A.Gray Calamagrostis pinetorum Swallen Calamagrostis pisinna Swallen Calamagrostis pittieri Hack. Calamagrostis planifolia (Kunth) Trin. ex Steud. Calamagrostis poluninii T.J.Sørensen Calamagrostis polycephala Vaniot Calamagrostis polygama (Griseb.) Parodi Calamagrostis × ponojensis Montell Calamagrostis porteri A.Gray Calamagrostis × prahliana Torges Calamagrostis preslii (Kunth) Hitchc. Calamagrostis pringlei Beal Calamagrostis przevalskyi Tzvelev Calamagrostis × pseudodeschampsioides Tzvelev Calamagrostis pseudophragmites (Haller f.) Koeler Calamagrostis pungens Tovar Calamagrostis purpurascens R.Br. Calamagrostis purpurea (Trin.) Trin. Calamagrostis pusilla Reeder Calamagrostis quadriseta (Labill.) Spreng. Calamagrostis radicans Vaniot Calamagrostis ramonae Escalona Calamagrostis rauhii Tovar Calamagrostis recta (Kunth) Trin. ex Steud. Calamagrostis reflexa (Vickery) Govaerts Calamagrostis reitzii Swallen Calamagrostis × rigens Lindgr. Calamagrostis rigescens (J.Presl) Scribn. Calamagrostis rigida (Kunth) Trin. ex Steud. Calamagrostis rodwayi (Vickery) Govaerts Calamagrostis rosea (Griseb.) Hack. Calamagrostis rubescens Buckley Calamagrostis rupestris Trin. Calamagrostis sachalinensis F.Schmidt Calamagrostis sajanensis Malyschev Calamagrostis salina Tzvelev Calamagrostis scaberula Swallen Calamagrostis scabrescens Griseb. Calamagrostis scabriflora Swallen Calamagrostis sclerantha Hack. Calamagrostis sclerophylla (Stapf) Hitchc. Calamagrostis scopulorum M.E.Jones Calamagrostis scotica (Druce) Druce Calamagrostis sesquiflora (Trin.) Tzvelev Calamagrostis setiflora (Wedd.) Pilg. Calamagrostis sichuanensis J.L.Yang Calamagrostis sikangensis (Keng) P.C.Kuo & S.L.Lu ex J.L.Yang Calamagrostis sinelatior (Keng) P.C.Kuo & S.L.Lu ex J.L.Yang Calamagrostis smirnowii Litv. ex Petrov Calamagrostis spicigera (J.Presl) Steud. Calamagrostis spruceana (Wedd.) Hack. ex Sodiro Calamagrostis srilankensis Davidse Calamagrostis staintonii G.Singh Calamagrostis stenophylla Hand.-Mazz. Calamagrostis steyermarkii Swallen Calamagrostis stolizkai Hook.f. Calamagrostis stricta (Timm) Koeler Calamagrostis × strigosa (Wahlenb.) Hartm. Calamagrostis subacrochaeta Nakai Calamagrostis × subchalybaea Tzvelev Calamagrostis × subepigeios Tzvelev Calamagrostis sublanceolata Honda Calamagrostis × submonticola Prob. Calamagrostis × subneglecta Tzvelev Calamagrostis suka Speg. Calamagrostis tacomensis K.L.Marr & Hebda Calamagrostis tarmensis Pilg. Calamagrostis tashiroi Ohwi Calamagrostis × tatianae Prob. Calamagrostis teberdensis Litv. Calamagrostis teretifolia Laegaard Calamagrostis tianschanica Rupr. Calamagrostis tibetica (Bor) Tzvelev Calamagrostis tolucensis (Kunth) Trin. ex Steud. Calamagrostis × torgesiana Hausskn. Calamagrostis trichodonta (Wedd.) Soreng Calamagrostis turkestanica Hack.