Saccifoliaceae Maguire and Pires
~ Gentianaceae
Habit and leaf form. Shrubs. Leaves small; alternate; spiral (closely crowded towards the branch tips); imbricate; petiolate; simple. Lamina entire; obovate (spathulate); seemingly parallel-veined (see illustration in the original description); seemingly cross-venulate; attenuate at the base. Leaves exstipulate. Lamina margins entire; revolute (and the lamina externally pouched at the apex).
Leaf anatomy. Stomata present; mainly confined to one surface (borne on (confined to?) the inner surface of the pouch); anisocytic.
Adaxial hypodermis absent. The mesophyll without calcium oxalate crystals.
Stem anatomy. Internal phloem present. Secondary thickening developing from a conventional cambial ring. Xylem with vessels. Vessel end-walls scalariform. Wood parenchyma lacking.
Reproductive type, pollination. Plants hermaphrodite. Floral nectaries represented by glands at the bases of the sepals?.
Inflorescence, floral, fruit and seed morphology. Flowers solitary; axillary; fairly showy; regular; (4)5 merous; cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk absent.
Perianth with distinct calyx and corolla; (8)10; 2 whorled; isomerous. Calyx (4)5; 1 whorled; gamosepalous (basally); regular. Corolla (4)5; 1 whorled; gamopetalous; lobes imbricate; with a well developed tube; regular.
Androecium (4)5. Androecial members adnate; all equal; free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 5; inserted near the base of the corolla tube, or midway down the corolla tube (halfway or more down); isomerous with the perianth; oppositisepalous; alternating with the corolla members; filantherous (the filaments quite long, but the anthers enclosed by the corolla). Anthers basifixed; non-versatile; dehiscing via longitudinal slits; latrorse to introrse; tetrasporangiate; appendaged. The anther appendages apical (by extension of the connective into an evident point). Pollen shed as single grains. Pollen grains aperturate; 3 aperturate; colporate.
Gynoecium 2 carpelled. Carpels reduced in number relative to the perianth. The pistil 2 celled. Gynoecium syncarpous; synstylovarious to eu-syncarpous; superior. Ovary 2 locular (but the partitions imperfect towards the apex); sessile. Gynoecium stylate. Styles 1; more or less attenuate from the ovary; apical; much longer than the ovary (but included). Stigmas 12 (shortly bilobed). Placentation axile (distally intruded-parietal). Ovules 3070 per locule (many); anatropous; unitegmic (the single integument massive); tenuinucellate.
Fruit unknown.
Physiology, biochemistry. Alkaloids seemingly absent. Iridoids apparently detected.
Peculiar feature. Lamina exhibiting revolute margins continuous with a characteristic, abaxially pouched tip.
Geography, cytology. Neotropical. Guayana Highland.
Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgrens Superorder Gentianiflorae (?); Gentianales (?). Cronquists Subclass Asteridae; Gentianales. APG (1998) Eudicot; core Eudicot; Asterid; Euasterid I; Gentianales (as a synonym of Gentianaceae). Species 1. Genera 1; only genus, Saccifolium.
Maguire and Pires 1978.
Cite this publication as: ‘L. Watson and M. J. Dallwitz (1992 onwards). The Families of Flowering Plants: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 14th December 2000. http://biodiversity.uno.edu/delta/’. Dallwitz (1980), Dallwitz, Paine and Zurcher (1993, 1995, 2000), and Watson and Dallwitz (1991) should also be cited (see References).