Plants — 23,508 Species

Yellow-flowered Cryptantha

Oreocarya confertiflora Greene

Oreocarya confertiflora is an erect perennial desert herb native to the southwestern United States, with yellow hairy flowers.

Miner's Candle

Oreocarya virgata (Porter) Greene

Miner's candle Oreocarya virgata is a white-flowered biennial herb native to Wyoming and Colorado, US.

Parry's goldenrod

Oreochrysum parryi (A.Gray) Rydb.

Oreochrysum parryi, Parry's goldenrod, is the only species in the Asteraceae genus Oreochrysum, native to western North America.

Longpedicel Woodnettle

Oreocnide pedunculata (Shirai) Masam.

Oreocnide pedunculata is an Urticaceae flowering shrub/tree native to East Asia, whose leaves feed local macaque species.

highland rush

Oreojuncus trifidus (L.) Záv.Drábk. & Kirschner

Oreojuncus trifidus is a perennial amphi-atlantic rush native to arctic, alpine and northern regions.

Mountain Parsley

Oreoselinum nigrum Delarbre

Tundra Aster

Oreostemma alpigenum (Torr. & A.Gray) Greene

Oreostemma alpigenum is a perennial/subshrub in Asteraceae from western US mountains, commonly called tundra aster or Anderson's mountain crown.

Oregano

Origanum vulgare L.

Origanum vulgare L., commonly oregano, is a herb related to marjoram with key growth and cultivation requirements outlined here.

Large-flowered Orlaya

Orlaya grandiflora (L.) Hoffm.

Orlaya grandiflora (white laceflower) is an Apiaceae annual native to Mediterranean Europe, popular in gardens.

Divergent Star-of-Bethlehem

Ornithogalum divergens Boreau

Ornithogalum divergens Boreau is a bulbous flowering plant native to a broad range from southern Europe to western Middle East.

Narbonne Star-of-Bethlehem

Ornithogalum narbonense L.

Ornithogalum narbonense is a bulbous flowering plant native to the Mediterranean, Armenia, and northwestern Iran that blooms from May to June.

Drooping Star-of-Bethlehem

Ornithogalum nutans L.

Drooping star-of-Bethlehem (Ornithogalum nutans) is a bulbous perennial flowering plant native to Europe and South West Asia.

Chincherinchee

Ornithogalum thyrsoides Jacq.

Ornithogalum thyrsoides Jacq. is a winter-dormant perennial flowering plant that has earned the RHS Award of Garden Merit.

common star-of-Bethlehem

Ornithogalum umbellatum L.

Ornithogalum umbellatum is a toxic bulbous geophyte used as an ornamental, with traditional culinary and medicinal uses.

Orange Bird's-foot

Ornithopus pinnatus (Mill.) Druce

Ornithopus pinnatus (orange birdsfoot) is a Fabaceae plant native to Western Europe, the Mediterranean, and Macaronesia.

Baja California birdbush

Ornithostaphylos oppositifolia (Parry) Small

Ornithostaphylos oppositifolia is a rare burl-forming woody plant native to southern California and Baja California, sometimes cultivated in native gardens.

Thyme Broomrape

Orobanche alba Steph. ex Willd.

Orobanche alba is a short parasitic annual that infects mint family plants, flowering May to June and pollinated by bumblebees.

Nodding Broomrape

Orobanche cernua Loefl.

Orobanche cernua, the nodding broomrape, is a holoparasitic herb growing up to 0.4 m, found across Eurasia.

Bean Broomrape

Orobanche crenata Forssk.

Orobanche crenata, or bean broomrape, is a chlorophyll-less parasitic plant that threatens legume production.

ivy broomrape

Orobanche hederae Duby

Orobanche hederae Duby, or ivy broomrape, is a parasitic plant that grows on ivy across Europe and parts of Asia.

Common Broomrape

Orobanche minor Sm.

Orobanche minor Sm., common broomrape, is a parasitic perennial herb native to Southern Europe, introduced widely elsewhere.

Hairy Broomrape

Orobanche pubescens d'Urv.

Orobanche pubescens is a self-supporting annual herb in Orobanchaceae that grows up to 0.17 m.

greater broomrape

Orobanche rapum-genistae Thuill.

Orobanche rapum-genistae (greater broomrape) is a chlorophyll-free perennial parasitic plant found across Western Europe and North Africa.

Golden Club

Orontium aquaticum L.

Orontium aquaticum (golden-club) is the only living species in the Orontium genus, endemic to the eastern US, with a long-debated floral structure.