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The families of flowering plants

L. Watson and M.J. Dallwitz

Sparganiaceae Schultz-Schultzenst.

~ Typhaceae.

Habit and leaf form. Marsh or aquatic herbs. Perennial; without conspicuous aggregations of leaves; rhizomatous. Hydrophytic to helophytic; rooted, or free floating (less often). Leaves emergent and floating. Leaves alternate; distichous; sessile; sheathing; simple. Lamina entire; linear; parallel-veined; without cross-venules. Leaf development ‘graminaceous’ (?).

General anatomy. Plants with silica bodies.

Leaf anatomy. Stomata present; paracytic. The mesophyll containing mucilage cells (with raphides), or not containing mucilage cells; containing crystals. The crystals raphides, or druses, or solitary-prismatic. Foliar vessels present; with scalariform end-walls. Minor leaf veins without phloem transfer cells.

Axial (stem, wood) anatomy. Secondary thickening absent.

The vessel end-walls scalariform.

Root anatomy. Root xylem with vessels; vessel end-walls scalariform.

Reproductive type, pollination. Fertile flowers functionally male and functionally female. Plants monoecious (the inflorescence system basally female, apically male). Floral nectaries absent (? — no septal nectaries). Pollination anemophilous.

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’. The ultimate inflorescence units racemose. Inflorescences axillary; of globose units, each comprising twice- or thrice-compound heads. Flowers bracteate (female flowers, usually), or ebracteate (male flowers, usually); small; regular to very irregular (according to their location in the inflorescence). The floral irregularity involving the perianth and involving the androecium. Flowers cyclic. Floral receptacle developing an androphore. Perigone tube absent.

Perianth of ‘tepals’; (1–)3–4(–6); free; 1 whorled, or 2 whorled; isomerous, or anisomerous; sepaloid (scaly).

Androecium (1–)3(–6) (depending on position in the inflorescence). Androecial members free of the perianth; free of one another, or coherent (filaments sometimes fused basally); 1 whorled, or 2 whorled. Androecium exclusively of fertile stamens. Stamens (1–)3(–6); reduced in number relative to the adjacent perianth to diplostemonous. Anthers basifixed; non-versatile; extrorse (when ascertainable); tetrasporangiate. Microsporogenesis successive. Tapetum amoeboid. Pollen shed as single grains. Pollen grains aperturate; 1 aperturate; ulcerate (the aperture diffusely delimited); 2-celled.

Gynoecium 1 carpelled, or 2 carpelled. Carpels reduced in number relative to the perianth. The pistil 1 celled, or 2 celled. Gynoecium monomerous, or syncarpous (in the latter case, pseudomonomerous, with one locule empty); of one carpel, or synovarious to synstylovarious; superior. Carpel apically stigmatic; 1 ovuled. Placentation apical. Ovary when detectably syncarpous, 2 locular. Gynoecium stylate. Styles 2; free to partially joined; attenuate from the ovary. Stigmas dry type; papillate; Group II type. Placentation when pseudomonomerous, apical. Ovules 1 per locule; pendulous; anatropous; bitegmic; crassinucellate. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; proliferating (forming up to 150 cells); ephemeral. Synergids pear-shaped. Endosperm formation helobial. Embryogeny onagrad.

Fruit fleshy to non-fleshy. The fruiting carpel indehiscent; drupaceous, or nucular. Fruit when detectably pseudomonomeric or syncarpous, indehiscent; a drupe, or a nut. The drupes with one stone. Fruit 1 seeded. Seeds endospermic. Endosperm oily. Perisperm present (thin). Seeds with starch. Cotyledons 1. Embryo achlorophyllous (1/1); straight. Testa without phytomelan; very thin.

Seedling. Hypocotyl internode present (short). Mesocotyl absent. Seedling collar not conspicuous. Cotyledon hyperphyll elongated; assimilatory; more or less circular in t.s. Coleoptile present. Seedling cataphylls absent. First leaf dorsiventral. Primary root ephemeral.

Physiology, phytochemistry. C3. C3 physiology recorded directly in Sparganium. Anatomy non-C4 type (Sparganium). Accumulated starch exclusively ‘pteridophyte type’. Not cyanogenic. Alkaloids present, or absent. Saponins/sapogenins absent. Proanthocyanidins present; cyanidin. Flavonols present; quercetin and myricetin. Ellagic acid absent. Sieve-tube plastids P-type; type II.

Geography, cytology. Frigid zone and temperate, tropical (a few). Widespread North temperate, also Southeast Australia and New Zealand - and a few in Borneo and New Guinea. X = 15.

Taxonomy. Subclass Monocotyledonae. Dahlgren et al. Superorder Bromeliiflorae; Typhales. APG III core angiosperms; Superorder Lilianae; commelinid Monocot. APG IV Order Poales (as a synonym of Typhaceae).

Species 20. Genera 1; only genus, Sparganium.

General remarks. These compiled data show Sparganium differing conspicuously from Typha in the inflorescence, floral, fruit and seed morphology, as well as in ‘esoteric characters’ depending on limited sampling (papillate stigmas, embryological details, seedling morphology).

Illustrations. • Le Maout and Decaisne: Sparganium. • Sparganium angustifolium: as S. affine, Eng. Bot. 1389 (1869). • Sparganium emersum (B. Ent.). • Sparganium emersum: as S. simplex, Eng. Bot. 1388 (1869). • Sparganium erectum var. erectum: as S. ramosum, Eng. Bot. 1387 (1869). • Sparganium natans: as S. minimum, Eng. Bot. 1390 (1869).

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.’.