Explore 23,508 Species
Black Tupelo
Nyssa sylvatica Marshall
Nyssa sylvatica Marshall, the black tupelo, is a long-lived North American decid…
pennywort
Obolaria virginica L.
Obolaria virginica, or Virginia pennywort, is a small perennial mycoheterotrophi…
hammock fern
Oceaniopteris cartilaginea (Sw.) Gasper & Salino
Oceaniopteris cartilaginea, the gristle or soft water fern, is a resilient fern …
showy plane
Ochna natalitia (Meisn.) Walp.
peeling plane
Ochna pulchra Hook.
Ochna pulchra Hook. is a distinctively barked African tree that indicates Gifvel…
Small-leaved plane
Ochna serrulata (Hochst.) Walp.
Ochna serrulata is a South African native shrub cultivated ornamentally that has…
Balsa Tree
Ochroma pyramidale (Cav.) Urb.
Ochroma pyramidale, commonly called balsa, is a fast-growing American tree famou…
whorled wood aster
Oclemena acuminata (Michx.) Greene
Oclemena acuminata is a perennial herb native to eastern North America that can …
bog aster
Oclemena nemoralis (Aiton) Greene
Oclemena nemoralis is a perennial herb native to northeastern North America, gro…
Pinebarren Aster
Oclemena reticulata (Pursh) G.L.Nesom
Oclemena reticulata is a perennial herbaceous flowering plant native to the sout…
Yellow Odontites
Odontites luteus (L.) Clairv.
Odontites luteus is an annual hemiparasitic yellow-flowered plant found in Europ…
Red Bartsia
Odontites vernus (Bellardi) Dumort.
Red bartsia (Odontites vernus) is a partial parasitic wildflower native to Euras…
Red Odontites
Odontites vulgaris Moench
Odontites vulgaris is a flowering plant in Orobanchaceae native from Europe to S…
Cardinal’s guard
Odontonema cuspidatum (Nees) Kuntze
Odontonema cuspidatum is an Acanthaceae plant species endemic to Mexico that has…
Firespike
Odontonema tubaeforme (Bertol.) Kuntze
Odontonema tubaeforme is an upright ornamental shrub native to Central America t…
Fairy Fern
Odontosoria chinensis (L.) J.Sm.
Odontosoria chinensis, commonly lace fern, is a Lindsaeaceae fern native to trop…
Square Perdekaroo
Oedera squarrosa (L.) Anderb. & K.Bremer
Oedera squarrosa is a small South African shrublet with dense small leaves and y…
Osoberry
Oemleria cerasiformis (Torr. & A.Gray ex Hook. & Arn.) J.W.Landon
Oemleria cerasiformis is a dioecious deciduous shrub native to Pacific North Ame…
Fine-leaved Water-dropwort
Oenanthe aquatica (L.) Poir.
Oenanthe aquatica, or fine-leaved water-dropwort, is a wetland umbellifer herb n…
Hemlock Water-dropwort
Oenanthe crocata L.
Oenanthe crocata (hemlock water-dropwort) is a toxic European perennial wetland …
Java water-dropwort
Oenanthe javanica (Blume) DC.
Oenanthe javanica is an edible perennial herb that is officially invasive in sev…
Corky-fruited Water-dropwort
Oenanthe pimpinelloides L.
Oenanthe pimpinelloides (corky-fruited water-dropwort) is a European perennial u…
water parsley
Oenanthe sarmentosa C.Presl ex DC.
Oenanthe sarmentosa, commonly water parsley, is a North American wetland perenni…
Oenothera affinis Cambess.
Oenothera affinis Cambess.
