For instance, the blue and red pimpernel, which are considered by most botanists as varieties, are said by Gartner to be quite sterile when crossed, and he consequently ranks them as undoubted species.
Adibidez, pimpernel urdin eta gorriari buruz, botanikari gehienek aldakitzat hartzen dituztenez, Gärtnerrek dio gurutzatzen direnean erabat antzuak direla, eta, beraz, dudarik gabeko espezietzat sailkatzen ditu.