アメリカナデシコはナデシコ科ナデシコ属の栽培種。日本へは明治時代に渡来し、別名ヒゲナデシコ（髭撫子）又はビジョナデシコ（美女撫子）とも呼ばれる。茎の頂部に頭状に花が集まった花序をつくり、苞の先が細長く、花の周りに多数突き出るのが特徴。
　多年草、高さ30～60㎝（矮性品種は15～20㎝）、根茎は±丈夫。根生葉は披針形～倒披針形。茎葉は±披針形。頭状花序に密に花が4～20+個、束生する。苞が4～6個つき、下部は卵形、縁は膜質で縁毛があり、先は長く尖鋭形でひげ状（±線形）になり、長さがほとんど、咢筒以上。これがヒゲナデシコの別名の由来。花柄は長さ0～3㎜。咢は長さ1.5～1.8（2.3）㎝、無毛、肋は40本、咢片は披針形、先は鋭形～尖鋭形。花弁の拡大部は長さ6～10㎜、白色～ピンク色、紫色、青紫色(violet)又は2色。果実は果柄が長さ3～4㎜。2n=30。花期は4～6月。園芸品種が多数ある。
品種)　 (Nigrescens Group) 'Sooty' (p,a) , Auricula Eyed Mixed (p,a) , Barbarini Series , Baron Breanthus = 'Hilbrebar' (PBR) , 'Big Time Deep Purple With Eye' (Big Time Series) , 'Big Time Red With Eye' (Big Time Series) , 'Big Time Scarlet' (Big Time Series) , 'Big Time White' (Big Time Series) , 'Big Time White With Deep Red Ring' (Big Time Series) , 'Black Adder' (p,a) , 'Black Magic , 'Bodestolz' , 'Breagreen' (PBR) , 'Darkest of All' , 'Dash Crimson' (Dash Series) (p,a) , 'Dash Magician' (Dash Series) (p,a) , 'Diabunda Purple Picotee' (Diabunda Series) (p,a) , 'Diabunda Red' (Diabunda Series) (p,a) , 'Diabunda Rose' (Diabunda Series) (p,a) , 'Donnet's Variety' (p,a) , 'Double Mixed' , Duke Breanthus = 'Hilbreduk' (PBR) , Duplex' , 'Duplex Mixed' , 'Dwarf Double Pinocchio Mixed' , 'Earlibird Mixture' , 'Electron Auricula-eyed Mixed' , 'Excelsior Mixed' , 'Festival Cherry' (Festival Series) , 'Festival Crimson' (Festival Series) , 'Festival Deep Violet' (Festival Series) , 'Festival Light Pink' (Festival Series) , 'Festival Lilac' (Festival Series) , 'Festival Pearl' (Festival Series) , Festival Raspberry' (Festival Series) (p,a) , 'Festival Red' (Festival Series) (p,a) , 'Festival Rose' (Festival Series) , 'Festival Salmon' (Festival Series) , 'Festival Violet' (Festival Series) , 'Festival Violet Picotee' (Festival Series) , 'Festival White' (Festival Series) , 'Festival White Flame' (Festival Series) (p,a) , Fine Mixed Early Summer Scented , Fragrant Cloud Mixed = 'Bodestolz Mixed' , Green Trick = 'Temarisou' (PBR) (p,a) , 'Heart Attack' (p,a) , 'Heritage Crimson' (Heritage Series) , 'Heritage Purple' (Heritage Series) , 'Heritage Rose Eye' (Heritage Series) , 'Heritage White' (Heritage Series) , 'Hilbrebar'(PBR) , 'Hilbreduk' , 'Hilbregremag' (PBR) 'Hilbreking' (PBR) , 'Hilbrelord' (PBR) , 'Hilbrequeen'(PBR) , 'Hollandia , 'Indian Carpet' (p,a) , 'Kaleidoscope' , King Breanthus = 'Hilbreking' (PBR) , 'Magic Charms Coral' (Magic Charms Series) , 'Magic Charms Crimson' (Magic Charms Series) , 'Magic Charms Pink' (Magic Charms Series) , 'Magic Charms Scarlet' (Magic Charms Series) , 'Magic Charms White' (Magic Charms Series) , Messenger Group(p,a) , 'Messenger Red' , 'Messenger Red/white' , 'Messenger Scarlet' , 'Messenger White' , Midget Group (p,a) , 'Monksilver Black' (p,a) , 'New Era' , Nigrescens Group (p,a) , 'Noverna Clown' (Noverna Series) , 'Noverna Coral' (Noverna Series) , 'Noverna Pink' (Noverna Series) , 'Noverna Purple' (Noverna Series) , 'Noverna Salmon/white Eye' (Noverna Series) , 'Noverna Series Formula Mixed' , 'Noverna Violet' (Noverna Series) , 'Noverna White' (Noverna Series) , 'oeschberg' (p,a) , 'Padingreen' (PBR) , 'Pink Beauty Improved' , 'Princess' , Queen Breanthus = 'Hilbrequeen' (PBR) , 'Red Romance' (p,a) , 'Roseus' (p,a) , Summer Sundae = 'Summer Sun' , 'Super Double Mixed' , 'Super Duplex Mixed' , 'Super Parfait Raspberry'(Super Parfait Series) (p,a) , 'Super Parfait Strawberry' (Super Parfait Series) (p,a) , 'Sweet Coral' (Sweet Series) , 'Sweet Purple'(Sweet Series) , 'Sweet Red' (Sweet Series) , 'Sweet Scarlet' (Sweet Series) , Sweet Series (p,a) , 'Sweet White' (Sweet Series) , 'Temarisou'(PBR) , 'Tuxedo Black' (p,a) , 'Wee Willie' , 'Woodfall'