Ponderosa lemon
The ponderosa lemon originated in roughly 1887, and is believed to come from a chance seedling grown in Hagerstown, Maryland. It was later named and introduced to the nursery trade in 1900. Though often referred to as a cross between the lemon and citron, a recent genomic analysis showed it to solely contain pomelo ("Citrus maxima") and citron ("Citrus medica") DNA, perhaps being an F2 hybrid. Thus they cannot derive from true lemons, which have a mandarin orange component.
Sweet lemon
Sweet lemon and sweet lime refer to many citrus hybrids that contain low acid pulp and juice. They are hybrids often similar to non-sweet lemons or limes, but with less citron parentage. Sweet limes and lemons are not sharply separated:
The same plant may also be known by different names:
The sweet lemons and sweet limes are not derived from either lemons or the more common limes, nor do they represent a monophiletic grouping, having arisen from distinct citrus hybridizations. Plants and fruits with the common name sweet lemon or sweet lime include: