in describing from Taxonomic Problems in Cochinchina (presently Cambodia, Laos, Vietnam). This is the origin of Cultivated Liriopogons the plants known presently as L. spicata. Ker-Gawl (1807) proposed the genus based on Thun-

1 berg’s that he recognized as Paul R. Fantz misassigned to the genus Convallaria. Ker-Gawl (1821) assigned Loureiro’s foliage. may be green or varie- species to Ophiopogon as O. spicatus. Additional index words. nomencla- ture, Liriope, Ophiopogon, Convallaria- gated with marginal bands, longitudi- Siebold (1830) described the spe- ceae, , ornamentals, ground nal stripes, or, occasionally, with trans- cies Slateria jaburan from Japan. covers verse bands of creams, yellows, white, Loddiges (1832) assigned Siebold’s or silver. species to Ophiopogon, presently known Summary. Liriopogons (Liriope, Liriopogons commonly are as O. jaburan. Ophiopogon) are versatile landscape known under several vernacular names Decaisne (1868) described the plants with a complexity of taxonomic in the trade, “lilyturfs” (usually ap- species O. . This is the origin of problems. A taxonomic revision of plied to Liriope spp.), “mondo grass” the currently known in the trade liriopogons cultivated in the United (usually applied to Ophiopogon spp.), as L. muscari. States is needed; one that includes an and “monkey grass” and “Aztec grass” Nakai (1920) described the spe- inventory of taxa, quantitative descriptions of species and , (both applied across generic lines). cies O. planiscapus presently known in keys and other aids for segregation They are versatile landscape plants, cultivation. This is the last of the five and identification of taxa, documenta- being used as , founda- commonly known cultivated species tion of taxa with vouchers deposited tion plants, understory plants for woody to be described. in herbaria, and establishment of a crops, edging and massing, and in Farwell (1921) reported that the living germplasm collection that can combination with a wide variety of generic name Mondo (Adanson 1763) serve as a standard for the nursery/ perennials, shrubs, and trees. had priority over Ophiopogon. Farwell landscape industries. Liriopogons are noted as durable, transferred all species to the genus adaptable low-maintanence evergreens Mondo. Lacking common names, this with no serious pest problems. They is the probable source of plants in the ailey (1929) used the term are moderately drought-resistant and genus becoming known as “mondo Liriomondos to refer to culti- useful in sun or shade (Adams, 1989; grasses” in cultivation. B vated members of the genera Batson, 1984; Dirr, 1983; Flint, 1983; Bailey (1929) provided the first Liriope Lour. and Mondo (Kaempf.) Halfacre and Shawcroft, 1989; Hudak, major treatment of this cultivated group Adans. The name Ophiopogon Ker- 1985; Hume and Morrison, 1963; of plants, referring to them as Gawl. has been conserved according Odenwald and Turner, 1980; Skinner, liriomondos or lilyturfs. He summa- to the international rules (Voss 1983), 1971; Still, 1988; Thomas, 1982; Voigt rized their cultural uses and nomencla- thus reducing the name Mondo to syn- et al., 1983; Wyman, 1977). tural history. onymy, and recognizing Ophiopogon Liriopogons are becoming an in- Bailey noted that several authors as the correct name for this genus. creasingly important landscape crop in combined the taxa under one genus, Accordingly, Bailey’s Liriomondos was today’s trade. Nurseryworkers, land- but correctly concluded that there were altered by Skinner (1971) to scapers, and recent authors (Adams, two differentiated genera named Liriopogons, a useful name when dis- 1989; Batson, 1984; Dirr, 1983; Flint, Mondo Adans. (syn. Ophiopogon Ker- cussing the complex group because it 1983; Halfacre and Shawcroft, 1989; Gawl) and Liriope Lour. A key was is difficult in the nursery/landscape Hudak, 1985; Hume and Morrison, provided to the seven species of Mondo industries to identify species and seg- 1963; Odenwald and Turner, 1980; and two species of Liriope, along with regate the genera. Bailey (1929) noted Skinner, 1971; Still, 1988; Thomas, descriptions. No cultivars were noted. “the plants are commonly misnamed 1982; Voigt et al., 1983; Wyman, Bailey transferred Descaisne’s name to in nurseries and the pictures in books 1977) currently recognize five species Liriope as L. muscari and described are not reliable; specimens are likely to in the trade, namely L. muscari briefly two varieties as var. variegata be wrongly determined in herbaria.” (Decne.) Bailey, L. spicata Lour., O. and var. exiliflora. The liriopogons are acaulescent jaburan (Sieb.) Lodd., O. japonicus Bailey’s species M. japonicum plants with grass-like leaves and small, (Thunb.) Ker-Gawl, and O. planiscapus Farw., M. jaburan (Sieb.) Bailey, M. lilac to violet or white clus- Nakai. The taxonomic problems of planiscapum (Nakai) Bailey, L. spicata tered in fascicles on scapes among the liriopogons have increased in com- Lour. and L. muscari (Decne.) Bailey plexity since Bailey, as outlined below. are commonly known cultivated spe- cies in the United States. Mondo dracae- Taxonomic history Department of Horticultural Science, North Carolina noides (Bak.) Farw., M. intermedium State University, Box 7609, Raleigh, NC 27695-7609. Thunberg (1780) described the (D. Don) Bailey, and M. wallichianum 1 species Convallaria japonica. This is Professor. (Kunth) Bailey are not currently re- the origin of plants known today as O. Research Project NC0 6104 funded by the North Caro- ported to be in cultivation as lirio- lina Agricultural Research Service, Raleigh, NC japonicus. pogons. 27695-7643. Loureiro (1790) proposed the The Sixth International Botanic

146 HortTechnology · Apr./June 1993 3(2) Congress met in Amsterdam in 1935. (1983) cited L. muscari auth. (non cally are brief. They often use charac- A number of generic names were con- Bailey) as a synonym of L. graminifolia teristics that could apply to several served over synonyms and earlier pub- Baker. Hara (1984) recognized Bailey’s selections and relative terms that are lished generic names. These are in- transfer as legitimate and cited L. open to misinterpretation. Good quan- cluded in Appendix III of the “Inter- platyphylla Wang & Tang as a syn- titative descriptions are needed for national Code of Botanic Nomencla- onym of L. muscari Bailey, as did comparison and delimitation of taxa. ture,” the international rules govern- Huxley (1992). Third, identification aids are ing plant names. The generic name Skinner (1971) proposed the ver- scarce. Illustrated identification guides Ophiopogon was conserved over the nacular name “liriopogon” for this are limited. Taxonomists use keys— generic name Mondo as the correct cultivated group. His inventory of taxa dichotomous statements that present name for the genus. Rickett and Stafleu included brief descriptions of taxa. He contrasting morphological character- (1959) began publishing a list of con- adopted the name L. platyphylla based istics-to segregate taxa. Similar keys served and rejected names in Taxon, upon Meyer and Walker (1965) trans- are needed for liriopogons. the journal of the International Assn. ferring 15 names to this spe- Fourth, there is a lack of represen- for Plant . cies from L. muscari. He noted the tative specimens of species and culti- Hume (1961) provided a revised name O. arabicus as synonymous with vars deposited in herbaria. Vouchers treatment of the lilyturfs. He reported O. planiscapus, and noted O. inter- of identified liriopogons can be used that the generic name Mondo must be medius as apparently not cultivated in for morphological comparison and aid- abandoned in favor of the conserved America. ing identification of unknowns. Lirio- generic name Ophiopogon, following pogon specimens are rare to nonexist- the adoption by the International Taxonomic problems ent in some major herbaria in the Botanic Congress of Amsterdam in First, there is presently no thor- United States. Larger herbarium col- 1935. He recognized three species— ough inventory of the cultivated lections of liriopogons need critical O. jaburan, O. japonicus, and O. liriopogons. The major contributions examination as surveys of species re- arabicus [ = O. planiscapus] —the latter include Bailey (1929) and the more- veal mixed material filed under each name found without a published de- modern revisions by Hume (1961), name. This makes it difficult for one to scription. These are the same com- Hume and Morrison (1963), and Skin- ascertain the boundaries of the species monly cultivated species of mondo ner (1971). These moderninventories and identify unknown cultivated spe- grasses recognized by Bailey (1929). are incomplete and out-of-date; they cies. Botanical gardens and arboreta Hume (1961) also provided sev- recognize five species and nearly 20 are important repositories for living eral changes in his treatment of Liriope. cultivars. If one begins to assemble germplasm collections. Unfortunately, He recognized five species— L. mus- names of available liriopogons culti- liriopogons are represented poorly in cari, L. spicata, L. graminifolia (L.) vated in the United States based on these collections, and they frequently Bak., L. exiliflora (Bailey) Hume, and literature and catalogues, one can find contain mixed material filed under one L. gigantea Hume—the latter pair new- more than 20 named species (Table 1) name. ly described. He also described culti- and more than 100 named cultivars Fifth, there is no revision geo- vars for the first time, including ‘Vittata’ (Table 2), even after elimination of graphically or monograph of lirio- of O. jaburan and 11 cultivars of L. similar names. pogons worldwide. Liriopogons are muscari: ‘Big Blue’, ‘Blue Spire’, Second, detailed descriptions of native to Asia, introduced into the ‘Christmas Tree’, ‘Curly Twist’, ‘Ele- taxa are lacking, both at the level of United States via cultivation; how- ven-O-Three’, ‘Gold-banded’, ‘Lilac species and cultivars. Descriptions typi- ever, most Asian countries lack floras. Beauty’, ‘Majestic’, ‘Monroes White’, This lack of key literature references is ‘Silver Banded’, and ‘Variegata’. No a major obstacle in being able to iden- key was provided to taxa. tify accurately those species that are Hume and Morrison (1963) pro- found in cultivation in the United vided cultural uses of lilyturfs and a States. brief inventory of additional new cul- Sixth, a number of nomenclatural tivars, including L. muscari: ‘Border questions need to be resolved, from Gem’, ‘Cockscomb’, ‘Grandiflora’, the family level downwards. An order- ‘New Wonder’, ‘Silvery Midget’, and ing of the nomenclature is needed to ‘Silvery Sunproof. provide the correct name for the taxon Wang and Tang (1951) rejected plus the available synonyms. Bailey’s transfer of Decaisne’s basionym Family. The familial relationship muscari and proposed a new name, L. of liriopogons is unclear among mod- platyphylla, for the commonly culti- ern botanists. Traditionally, lirio- vated species. Meyer and Walker pogons were included within the fam- (1965) published an English transla- ily Liliaceae, a family whose delimita- tion of Ohwi’s Flora of Japan, accept- tion is much disputed because of a ing the name L. muscari (Descn.) Bailey number of aberrant members, such as in synonymy of L. platyphylla Wang & the liriopogons. This has lead bota- Tang. However, Makino (1961) cited nists to assign liriopogons to the L. platyphylla Wang & Tang as a syn- Convallariaceae, Haemodoraceae, or onym of L. graminfolia Baker. Jessop Ophiopogonaceae. Dahlgren et al.

HortTechnology · Apr./June 1993 3(2) 147 proposed the name of L. platyphylla as correct for plants bearing the name L. muscari. This is the one species pres- ently cultivated in the United States with the largest number of named cultivars. Nurseryworkers appear to be unaware of this name change, despite Meyer and Walker (1965) and Skinner (1971) adopting this name and trans- ferring cultivars to the newer name. Some botanical gardens (e.g., United States National Arboretum; Royal Botanic Gardens, Kew) now bear this newer name on their labels. However, plants of L. platyphylla obtained from China by the North Carolina State Univ. Arboretum are not equivalent to our cultivated plants labeled as L. muscari. This is a complex nomencla- tural problem that needs to be re- solved. Cultivars. Differentiation of cul- tivars is particularly difficult. There are several complexes of closely related names, yet nurseryworkers recognize different selections. ‘Variegata’ is a common name applied to selections in several species, as is ‘Alba’, ‘Big Blue’, and ‘Majestic’. Nurseryworkers segre- gate cultivars according to mor- phology, floral color, inflorescence apex, and habit. Mularoni and Ander- son (1987) studied the influence of environmental factors, including tem- (1985) used anatomical, chemical, cy- foliage. Ophiopogon japonicusis identi- perature, photoperiod, and fertility on tological, developmental, embryologi- fied by its narrow leaves, creeping mat- the growth of one unnamed cultivar of cal, morphological, and palynological forming habit, short height, and blue L. muscari. They concluded that vari- studies to revise the monocot families. hidden among the foliage. Liriope ability associated with leaf morphol- They assigned liriopogons to the order spicata is identified as a creeper with ogy and color could be environ- , family Convallariaceae, tall, narrow leaves and scapes within mentally induced; thus, these were not tribe Ophiopogoneae, well-segregated the leaves. is identified appropriate taxonomic characters. from the traditional order Liliales, fam- as a clumper with broad leaves and Additional morphological characters ily Liliaceae. Cronquist (1988), the scapes above the leaves. Nurserywork- with quantitative components are recognized American authority, main- ers have more difftculty identifying needed for delimitation of cultivars tained the traditional view of assigning Liriope sp. than Ophiopogon sp. due to and their segregation. liriopogons to the Liliaceae. their greater variability in growth habit, Cultural practices. Nursery- Genus. Genera are defined poorly leaf size, variegation, and flower color. workers use several cultural practices in the landscape/nursery trade. Nurs- There are impostors masquerad- that degrade cultivar integrity (Fantz eryworkers/landscapers appear to rely ing under several species names. For 1991a-c), and create nomenclatural on growth habit, leafwidth, and flower example, Hume’s (1961) L. exiliflora problems in liriopogons. Sexual repro- color as the main characters for segre- and L. gigantea are found within L. duction, for instance, is a leading cause gation. Therefore, plants frequently muscari. Nearly all nurseryworkers/ of taxonomic problems. Nurserywork- are misidentified to genus. Adams landscapers are unaware of these two ers obtain more propagules by harvest- (1989) reemphasized, and several ear- names proposed by Hume. Plants sold ing and growing from cultivars lier authors found, that flower posi- under the name O. japonicus includes than by divisions. Seedlings are as- tion was “the best characteristic for four species. Ophiopogon jaburan is a signed the same cultivar name as the identifying the genus,” with flowers of mystery to many in the trade who are parent plant from which seeds were Ophiopogon hanging down and flow- unfamiliar with the plant. Those famil- obtained, but the seedlings also con- ers of Liriope being erect. iar with “Aztec grass” regard it as a tain genetic information from an un- Species. Delimitation of species mutated Liriope because of its size, yet known parent. This practice results in is poorly understood in the trade. Nur- these plants actually belong to the modification of morphological expres- seryworkers/landscapers identify Ophi- genus Ophiopogon. sion, and cultivar degradation over opogon planiscapus by its purplish-black Wang and Tang (1951) of China time.

148 HortTechnology · Apr./June 1993 3(2) A second practice that causes cul- ing cultivars, keys, and other aids for Hara, H. 1984. Comments on East Asiatic tivar degradation is plant substitution. segregation and identification of plants (13). J. Jpn. Bot. 59(2):33-39. Some nurseryworkers substitute culti- liriopogons. The revision should also Hudak, J. 1985. Gardening with perenni- vars when filling an order without in- include an ordering of the nomencla- als. Timber Press, Beaverton, Ore. forming the customer of the substitu- ture, documentation of taxa with speci- tion or cultivar switch. mens deposited in herbaria, and estab- Hume, H.H. 1961. The Ophiopogon-Liriope A third cultural problem that leads lishment of a living collection that can complex. Baileya 9:135-58. to cultivar confusion is seedling inva- serve as a standard for the nursery— Hume, H.H. and B.Y. Morrison. 1963. The sion. Liriopogons are both field- and landscape industry. Germplasm accu- lilyturfs in gardens. Amer. Hort. Mag. container-grown. Seedling invasion can mulation of liriopogons was begun in 46(1):1-11. occur in field-grown crops by 1987 under the North Carolina Agri- Huxley, A., (ed.). 1992. The new Royal germination within a cultivar bed or by cultural Research Service project Horticultural Society dictionary of gar- invasion of a neighboring cultivar that NC03867 and continues as project dening. 3:95,376. is stoloniferous and produces daugh- NC06104 in order to resolve these ter plantlets. Yet, all plants harvested problems. Jessop. 1983. Liriope, p. 223-227. In C.G.G.J. van Steenis (ed.). Flora malesiana. from a bed are sold under the same vol. 9. Junk, The Hague, Netherlands. cultivar name. Seedling invasion also occurs when seeds from adjacent se- Literature Cited Ker-Gawl. 1807. . lections germinate in another cultivar’s Adanson, M. 1763. Familles des plantes. Curtis’ Bot. Mag. t. 1063. bed or pot. 2:496. Vincent, Paris. Ker-Gawl. 1821. Ophiopogon spicatus, blue- A fourth cultural practice causing Adams, G. 1989. Great ground covers. flowered snakesbeard. Edward’s Bot. Reg. cultivar identification problems is la- Amer. Nurseryman 170(8):83-91. t. 593. beling. Some nurseryworkers label beds Bailey, L. H. 1929. The case of Ophiopogon Liberty Hyde Bailey Hortorium. 1976. instead of individual plants. This re- Hortus Third: A concise dictionary of plants sults in cultivars being identified by and Liriope. Gentes Herbarum. 2(1):3- 37. cultivated in the United States and Canada. location, not by morphology. When 3rd ed. Macmillian, New York. windstorms, animals, customers, or Batson, W.T. 1984. Landscape plants for workers remove labels, they often are the Southeast. Univ. of South Carolina Loddiges, C. 1832. The botanical cabinet. replaced by the “guesstimate” method, Press, Columbia. 19(7):1876. Loddiges & Sons, London. leading to potential misidentification. Cronquist, A. 1988. The evolution and Loureiro, de, J. 1790. Flora Cochinchinensis Furthermore, workers copying plant classification of flowering plants. 2nd ed. 1:290. Labore, Ulyssipone [Lisboa]. labels can make spelling errors, such as Allen Press, Lawrence, Kan. Makino, T. 1961. New illustrated flora of observed in the names ‘Monroe’, Dahlgren, R.M.T., H.T. Clifford, and P.F. Japan. Hokuryukan Co., Ltd., Tokyo. ‘Monroe White’, ‘Munroe White’, Yeo. 1985. The families of the Monocoty- ‘Monroi White’, ‘Mooroe White’, and Meyer, F.G. and E.H. Walker (eds.). 1965. ledons: Structure, evolution and taxonomy. English translation of J. Ohwi, Flora of ‘Moores White’. Sometimes names are Springer-Verlag, New York. changed inadvertently, such as ‘Xmas Japan. Smithsonian Inst., Washington, D.C. Tree’ or ‘Xmas’, as a shortened form of Decaisne, J. 1868. Fl. des. Ser. 17:181. ‘Christmas Tree’. Dirr, M.A. 1983. Manual of woody land- Mularoni, T.C. and C.E. Anderson. 1987. Landscapers and nurseryworkers scape plants: Their identification, orna- Growth of Liriope muscari in response to are being held increasingly more ac- mental characteristics, culture, propaga- various temperature, photoperiod and nu- countable for correct plant names. tion and uses. Stipes, Champaign, Ill. trient combinations. North Carolina State Univ. Phytotron Rpt. p.36-49. Taxonomic problems create disputes Fantz, P.R. 1991a. Maintaining cultivar between some nurseryworkers, land- integrity: I. Identification ofcultivars. N.C. Nakai, T. 1920. Cat. Sem. Hort. Tokyo p. scapers, and their customers that may Assn. Nurserymen Nursery Notes 24(1): 33. have to be resolved by litigation. 20-23. Odenwald, N.G. and J.A. Turner. 1980. Conclusions Fantz, P.R. 1991b. Maintaining cultivar Plants for the South: A guide for landscape design. Claitor’s, Baton Rouge, La. Liriopogons are versatile land- integrity: II. Propagation ofcultivars. N.C. scape plants that are increasing in im- Assn. Nurserymen Nursery Notes 24(2): Quisumbing, E. 1951. Medicinal plants of 28-29,31-33. portance and use in today’s landscapes. the Philippines. Philippine Dept. Agr. Nat. There are several available species and Fantz, P.R. 1991c. Maintaining cultivar Resources Tech. Bul. 16:387-389. a multitude of cultivars being selected integrity: III. Cultivar substitution. N.C. Rickett, H.W. and F.A. Stafleu. 1959. and named. Species are often inter- Assn. Nurserymen Nursery Notes 24(3): Nomina generica conservanda et rejicienda mixed, with impostors and sold under 19-20. spermatophytorum I. Taxon 8(7):213- the same name. Farwell, O.A. 1921. Mondo Adans. Amer. 243. Taxonomically, liriopogons pre- Midland Naturalist 7:41-43. Siebold, C.T.E. 1830. Slateria. Verh. Bat. sent a complexity of problems that Flint, H.L. 1983. Landscape plants for east- Gen. 2:15. need to be resolved. A taxonomic revi- ern North America. Wiley, New York. sion of cultivated liriopogons grown in Skinner, H.T. 1971. Some liriopogon com- the United States is needed; one that Halfacre, D. and A. Shawcroft. 1989. Land- ments. J. Royal Hort. Soc. 96(8):345- includes an inventory of taxa, quanti- scape plants of the Southeast. 5th ed. Sparks, 350. tative descriptions of all taxa, includ- Raleigh, N.C. Still, S.M. 1988. Herbaceous ornamental

HortTechnology · Apr./June 1993 3(2) 149 plants. 3rd ed. Stipes, Champaign, Ill. Thomas, G.S. 1982. Perennial garden plants for the modern florilegium. 2nd ed. J.M. Dent & Sons, London. Thunberg, C.P. 1780. Convallaria japonica. Nov. Act. Reg. Soc. Upsala 3:208. Voigt, T.B., B.R. Hamilton, and F.A. Giles. 1983. Ground covers for the Midwest. Univ. of Illinois Printing Div., Champaign. Voss, E.G. 1983. International code of botanic nomenclature. Junk, The Hague, Netherlands. Wang F.T. and T. Tang. 1951. A new Liriope in cultivation but hitherto con- fused with a key to species of the genus. Acta Phytotax. Sin. 1(4):331-334. Whitcomb, C.E. 1976. Know it and grow it. Oil Capital Printing Co., Tulsa, Okla. Wyman, D. 1977 Wyman’s gardening en- cyclopedia. Macmillian, New York.

150 HortTechnology · Apr./June 1993 3(2)