The families of flowering plants

L. Watson and M.J. Dallwitz

Melanthiaceae sensu lato

~ Former Liliaceae.

Including Abaminaceae J.G. Agardh, Chionographidaceae, Cymbantheae (Cymbanthaceae) Salisb.(?), Heloniadaceae J.G. Agardh, Miyoshiaceae Makino, Nartheciaceae Fr. ex Bjurzon, Petrosaviaceae Hutch., Protoliriaceae Makino, Tofieldiaceae Takht., Veratraceae von Vest

Habit and leaf form. Herbs. Leaves well developed, or much reduced (Petrosavieae). Plants autotrophic, or parasitic (Petrosavieae); when parasitic, mycoheterotrophic; green and photosynthesizing (Japonolirion), or not green. Annual (rarely), or perennial; with a basal aggregation of leaves, or without conspicuous aggregations of leaves; rhizomatous (mainly), or tuberous, or cormous (rarely). Leaves alternate; spiral (usually), or distichous; flat; ‘herbaceous’, or membranous (Petrosavieae); sessile (usually), or petiolate (occasionally, almost); sheathing. Leaf sheaths not tubular. Leaves borne edgewise to the stem, or ‘normally orientated’; simple. Lamina entire; linear to lanceolate (usually), or ovate (rarely); parallel-veined. Leaves ligulate (Pleea), or eligulate.

Leaf anatomy. The leaf lamina dorsiventral (e.g. Melanthieae), or bifacial (e.g. Tofieldieae, Narthecium). The mesophyll containing mucilage cells (? — with raphides); commonly containing crystals. The crystals raphides, or solitary-prismatic. Foliar vessels absent.

Axial (stem, wood) anatomy. Secondary thickening absent. The axial xylem without vessels.

Root anatomy. Root xylem with vessels, or without vessels (in achlorophyllous forms); vessel end-walls scalariform.

Reproductive type, pollination. Plants hermaphrodite (nearly always), or dioecious, or polygamomonoecious. Floral nectaries present. Nectar secretion from the perianth (from the tepal bases in Narthecieae), or from the gynoecium (Petrosavia, Tofieldia, Zigadenus etc. with septal nectaries).

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in racemes, or in spikes, or in panicles. Inflorescences scapiflorous, or not scapiflorous; simple or compound racemes or spikes, rarely panicles. Flowers bracteate, or ebracteate; regular (nearly always), or very irregular (only in Chionographis); in Chionographis, zygomorphic; 3 merous; cyclic; usually pentacyclic. Perigone tube present (in hemi-epigynous forms), or absent. Hypogynous disk absent.

Perianth of ‘tepals’; 6; free to joined; 2 whorled (3+3); isomerous; sepaloid, or petaloid; without spots, or spotted (occasionally); similar in the two whorls; white, or yellow, or brown, or purple (bright yellow in Narthecium, but usually inconspicuous, usually lacking patterns and spurs).

Androecium 6, or 9 (Pleea), or 12 (Pleea). Androecial members free of the perianth; free of one another; 2 whorled (usually 3+3, Pleea with 6+3 or 6+6). Androecium exclusively of fertile stamens. Stamens 6 (usually), or 9 (Pleea), or 12 (Pleea); diplostemonous (usually), or triplostemonous to polystemonous (Pleea); normally alterniperianthial. Anthers dorsifixed (hypopeltate), or basifixed; dehiscing via longitudinal slits; extrorse (usually), or introrse (occasionally). Endothecium developing fibrous thickenings. The endothecial thickenings spiral. Microsporogenesis successive (usually), or simultaneous (Tofieldia). Anther wall initially with more than one middle layer; of the ‘monocot’ type. Tapetum glandular. Pollen grains aperturate; 1 aperturate (usually), or 2 aperturate, or 4 aperturate; sulcate (usually), or sulculate, or foraminate; 2-celled.

Gynoecium 3 carpelled. Carpels isomerous with the perianth. The pistil when syncarpous, 3 celled. Gynoecium apocarpous to syncarpous; semicarpous (the carpels often free above, and in Petrosavieae and Harperocallis free almost to their bases), or synovarious (usually, with separate styles), or synstylovarious (Aletris, with a tribrachiate style), or eu-syncarpous (sometimes, e.g. Tofieldia, with one style and a capitate stigma); superior, or partly inferior. Carpel when semicarpous, stylate; 2–100 ovuled (to ‘many’). Placentation marginal. Ovary when syncarpous, 3 locular; sessile. Gynoecium stylate. Styles 1, or 3; when three, free (Helonias, Heloniopsis), or partially joined; apical. Stigmas 1, or 3; of Veratrum dry type. Placentation axile. Ovules 2–100 per locule (to ‘many’); funicled; non-arillate; anatropous (usually), or campylotropous (Petrosavia); bitegmic; crassinucellate. Outer integument not contributing to the micropyle. Endothelium differentiated. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; proliferating (Veratrum). Endosperm formation helobial (by contrast with Liliales).

Fruit non-fleshy. The fruiting carpel when semicarpous, dehiscent; a follicle (opening along the inner suture). Fruit when syncarpous, dehiscent; a capsule. Capsules septicidal, or loculicidal (or opening ventricidally from apex to base, when the carpels are distally free, e.g. Tofieldia, Veratrieae). Seeds endospermic. Endosperm oily. Seeds usually winged (or with terminal appendages). Embryo well differentiated (but often small). Embryo ovoid or globose. Testa without phytomelan (by conrast with most capsular Asparagales, and also lacking phlobaphene).

Seedling. Hypocotyl internode present, or absent. Seedling collar not conspicuous. Cotyledon hyperphyll elongated; assimilatory; more or less circular in t.s., or dorsiventrally flattened (variously unifacial or bifacial). Coleoptile absent. Seedling cataphylls absent. First leaf ensiform (e.g. Tolfieldia), or dorsiventral (e.g. Zigadenus). Primary root ephemeral.

Physiology, phytochemistry. Inulin recorded (Gibbs 1974). Not cyanogenic. Alkaloids present (Veratreae), or absent. Saponins/sapogenins often present. Proanthocyanidins present, or absent; when present, cyanidin. Flavonols present, or absent; when present, kaempferol and quercetin. Ellagic acid absent.

Geography, cytology. Holarctic (mainly), Paleotropical, Neotropical. Frigid zone, temperate (mainly). Widespread N. temperate, E. Asia, Malaya, Borneo, the Americas, Arctic — not Africa, not Australia. Chromosomes with diffuse centromeres (Chionographis), or with normal centromeres. X = 8, 11, 12, 13, 15, 17.

Taxonomy. Subclass Monocotyledonae. Dahlgren et al. Superorder Liliiflorae; Melanthiales. APG III core angiosperms; Superorder Lilianae; non-commelinid Monocot. APG IV Order Laurales (Tofieldiaceae), or Alismatales (Petrosaviaceae), or Petrosaviales (Nartheciaceae), or Dioscoreales (Melanthiaceae s. str.).

Species about 140. Genera about 25; Amianthium, Anticlea, Chamaelirium, Chionographis, Helonias, Heloniopsis, Isidrogalvia, Lophiola, Melanthium, Metanarthecium, Nietneria, Protolirion, Schoenocaulon, Stenanthium, Toxicoscordion, Veratrum, Xerophyllum, Ypsilandra, Zigadenus (Melanthiaceae s. str.); Japanolirion, Petrosavia (Petrosaviaceae); Harperocallis, Pleea, Tofieldia, Triantha (Tofieldiaceae); Aletris, Lophiola, Narthecium (Nartheciaceae).

General remarks. An excellent treatment of Melanthiaceae sensu lato by Zomlefer (1997) is not accounted for here.

Illustrations. • Amianthium muscitoxicum: Addisonia 20 (1937–8). • Le Maout and Decaisne: Veratrum, Tofieldia, Amianthium (= Zigadenus). • Chionographis japonica: Bot. Mag. 106 (1880). • Helonias bullata: Addisonia 13 (1928). • Schoenocaulon officinale: as Sabadilla officinalis, Bot. Reg. 1839, 33. • Tofieldia calyculata: Hutchinson (1964). • Tofieldia palustris: Eng. Bot. 1543 (1869). • Isidrogalvia sessiliflora: Hook. Ic. Pl. 7–8 (1844). • Zigadenus elegans: as Z. glaucus, Bot. Reg. XXIV, 67 (1838). • Le Maout and Decaisne: Narthecium ossifragum. • Narthecium ossifragum (B. Ent.). • Petrosavia stellaris: Hutchinson (1964).

We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, genera included in each family, and classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG). See also Guidelines for using data taken from Web publications.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 5th March 2018.’.