A horticultural study of <i>Liriope</i> and <i>Ophiopogon</i>: Nomenclature, morphology, and culture
Liriopogons are evergreen perennials with a confusing taxonomy. New cultivars are being rapidly selected and named. The landscape industry uses them extensively and they are being planted in improper sites. Morphological studies were done at Louisiana State University in Baton Rouge, Louisiana to identify 19 cultivars by comparing plants to botanical keys. Cultural studies were done at Burden Station in Baton Rouge, Louisiana by comparing cultivars in sun and 63% shade, and by greenhouse fertilization experiments, and pruning experiments. Plants were harvested, studied, dried and mounted in the Louisiana State University Herbarium as permanent record.
Of the 19 cultivars of Liriope and Ophiopogon studied, there were two genera and eight species identified. These were studied for flower morphology on dissected flowers under microscope. Aztec grass, which had been labeled Ophiopogon jaburan was discovered to be Ophiopogon intermedius. Liriope muscari 'Big Blue' is a L. muscari but some plantings in landscapes are L. exiliflora. The cultivar 'Samantha' has been classified L. muscari and cf. to L. exiliflora, according to the rhizomatous root system and spaces between flowers. 'Evergreen Giant' and Supergreen Giant were both called cultivars of Liriope muscari and they are morphologically Liriope gigantea 'Evergreen Giant' and 'Merton Jacobs' Supergreen Giant™ respectively.
A three-year study at Burden Center with 19 cultivars, sun and 63% shade treatment and six replications showed the top sun performing cultivar to be Liriope gigantea 'Merton Jacobs' Supergreen Giant™. The second was Liriope muscari 'Big Blue'. Liriope muscari 'Monroe White' and Ophiopogon japonicus 'Silver Mist' were the two low sun performers. The top shade performers were O. japonicus and O. japonicus 'Nana'. The low sun performers were Liriope muscari 'Densiflora' and Liriope gigantea 'Evergreen Giant'.
Bib production benefited by 20% pruning in Ophiopogon intermedius but did not have significant effects on any other cultivar.
Plant height, quality, N and P were the most influenced variables for all combinations of liquid fertilization + controlled-release and liquid fertilizer alone over any of the controlled release rates of fertilization.
Index words: liriopogons, lilyturf, Liriope, Ophiopogon, mondo, Aztec grass, monkey grass, cultural practices, nomenclature, morphology.