Violaceae Batsch

Paula-Souza, J. & Ballard Jr, H.E. (2009). Neotropical Violaceae.

Morphology

Description

Herbs, subshrubs, shrubs, treelets or trees, less frequently lianas. Leaves alternate or less frequently opposite or pseudo- whorled , entire , serrate (the teeth bearing a terminal gland ) or rarely pinnatifid or lobed ; stipules present, persistent or deciduous . Inflorescences of fascicles, simple or compound cymes, (pseudo-) racemes, or flowers solitary, axillary . Flowers actinomorphic to strongly zygomorphic , bisexual or rarely unisexual, hypogynous; pedicels often articulated, bracteoles often present; aestivation usually apotact or less frequently quincuncial or convolute; sepals 5, free , equal or slightly unequal, rarely strongly unequal, persistent ; petals 5, free , equal or strongly unequal in zygomorphic flowers, the lowest petal being usually bigger and gibbose or spurred; stamens 5 or rarely 3, free or the filaments fused, anthers usually with a dorsal membranous connective appendage , the filaments usually with nectar glands (in zygomorphic flowers the large nectaries are born on the filaments of the 2 dorsal stamens and are enclosed in the lowest petal's sac or spur); ovary 3-carpellate or rarely 2-4-carpellate, ovules 1-many with  parietal placentation, style straight, curved or sigmoid . Fruit usually a leathery capsule , less frequently a woody or papery, bladder-like capsule , rarely a " berry " or nut ; seeds ( sub -) globose or less frequently strongly flattened and winged , discoid or irregularly angled, sometimes arillate, glabrous or less frequently pubescent .

Distribution

Distribution in the Neotropics

• Amphirrhox Spreng. - S Central America, N South America and E coast of  South America.
• Anchietea A.St.-Hil. - Widespread in South America.
• Corynostylis Mart. Gloeospermum Triana & Planch. - Central America, N South America.
• Fusispermum Cuatrec. - S Central America, N South America.
• Hekkingia H.E.Ballard & Munzinger - French Guiana, N Brazil (Roraima).
• Hybanthopsis Paula-Souza - endemic to Bahia state (Brazil).
• Hybanthus Jacq. - Widespread.
• Leonia Ruiz & Pav. - N South America.
• Mayanaea Lundell - Guatemala.
• Noisettia Kunth - N South America and E coast of South America.
• Orthion Standl. & Steyerm. - Central America.
• Paypayrola Aubl. - S Central America, N South America.
• Rinorea Aubl. - Central America, N South America and E coast of South America.
• Rinoreocarpus Ducke - N South America.
• Schweiggeria Spreng. - E Brazil.
• Viola L. - Widespread (mainly Central America and W South America).

Diagnostic

Other important characters

• Ovarysuperior, 3-carpellate with parietal placentation.
• Stipules present (although sometimes deciduous).
• Glands present at the tip of teeth on serrate leaves.
• Anthers provided with membranous connective appendages.
• Filaments provided with nectarglands.

Notable genera and distinguishing features

• Lianescent habit and strongly flattened seeds in Anchietea, Corynostylis and Hybanthopsis.
• Pappery, bladder-like capsules in Anchietea and Hybanthopsis.
• Capsules opening by a single londitudinal slit in Hybanthopsis.
• Auriculate sepals and pedicels not articulated in Viola.
• Sepals strongly unequal in Schweiggeria.
• Aestivation of petals convolute in Fusispermum.

General Description

Number of genera

17 genera:

• Amphirrhox  
• Anchietea 
• Corynostylis
• Fusispermum
• Gloeospermum  
• Hekkingia
• Hybanthopsis
• Hybanthus
• Leonia
• Mayanaea
• Noisettia
• Orthion
• Paypayrola 
• Rinorea
• Rinoreocarpus
• Schweiggeria
• Viola

Status

• All genera are endemic to the Neotropical region, except for Hybanthus, Rinorea and Viola.

Literature

Important literature

Eichler, A.W. 1871. Violaceae. In: Martius, K.F.P & Eichler, A.W. (eds.) Flora Brasiliensis. Monachii, Typographia Regia. 13 (1): 345-396.

Hekking, W. H. A. 1984. Studies on neotropical Violaceae: The genus Fusispermum. Proc. Kon. Ned. Akad. Wetensch., C 87(2): 121-130.

Hekking, W.H.A. 1988. Violaceae (Rinorea and Rioneocarpus). In: Flora Neotropica: 46 (1). The New York Botanical Garden. New York. 207p.

Morton, C.V. 1944. The genus Hybanthus in continental North America. Contr. US. Natl. Herb. 29: 74-82.

Munzinger, J.K & Ballard, H.E. 2003. Hekkingia (Violaceae), a New Arborescent Violet Genus from French Guiana, with a Key to Genera in the Family. Syst. Bot. 28 (2): 345-351.

Paula-Souza, J. & Souza, V.C. 2003a. Hybanthopsis, a new genus of Violaceae from Eastern Brazil. Brittonia. New York, U.S.A. 55 (2): 206 - 210.

Robyns, A. 1957. In: Woodson, R.E. & Schery, R.W. Flora of Panama. Ann. Missouri Bot. Gard. 54: 65-84.

Schulze, G.K. 1936. Morphologisch-systematische Studien über die Gattung Hybanthus mit besonderer Berücksichtigung der südamerikanischen Arten. Bot. Jahrb. Syst. 67: 437-492.

Smith, L.B. & Fernandéz-Pérez, A. 1954. Revisio Violacearum Colombiae. Caldasia 6 (28): 83-181.

Sparre, B. 1950. Estudios sobre las Violaceas Argentinas. Lilloa 23: 515-574.

Standley, P.C. & Williams, L.O. 1961. Flora of Guatemala 8. Fieldiana, Bot. 24, 7 (1): 70-82.

Okuoka, T. 2008. Molecular phylogenetic analysis of Violaceae (Malpighiales) based on plastid and nuclear DNA sequences. J.Plant Res. 121: 253-260.

Violaceae, N. K. B. Robson. Flora Zambesiaca 1:1. 1960

Habit

Shrubs or perennial or annual herbs (more rarely trees)

Leaves

Leaves alternate (rarely opposite or whorled), simple, entire or serrate to dentate (rarely ± dissected), usually with 2 stipules

Flowers

Flowers actinomorphic or, more often, ± zygomorphic, bisexual (rarely polygamous or dioecious)

Calyx

Sepals 5, free or shortly united, quincuncial or open in bud, usually persistent

Corolla

Petals 5, free, equal or ± unequal, the anterior one frequently ± spurred, imbricate, usually deciduous, alternating with the sepals

Androecium

Stamens 5, antisepalous, similar or ± dissimilar, the anterior pair in zygomorphic flowers with appendages which project into the spur, filaments free ± united, often forming a cylinder round the ovary; anthers usually introrse, free ± united, usually with a prolongation of the connective

Gynoecium

Ovary free, sessile, usually ± ovoid, 1-locular, with (2) 3 (4–5) parietal placentas each bearing 1–? ovules; styles completely united, usually thickened above, often ± S-shaped in zygomorphic flowers, stigma usually undivided

Fruits

Fruit a loculicidal capsule usually with contractile carinate valves, rarely a berry or nut

Seeds

Seeds sometimes with a small aril, usually with abundant endosperm

Violaceae, Hutchinson and Dalziel. Flora of West Tropical Africa 1:1. 1954

Habit

Herbs, shrubs, or small trees

Leaves

Leaves alternate or rarely opposite, stipulate

Flowers

Flowers actinomorphic or zygomorphic, from solitary to paniculate

Calyx

Sepals 5, imbricate

Corolla

Petals 5, nearly equal or the lower larger and often clawed, imbricate

Androecium

Stamens hypogynous, 5, alternate with the petals; anthers 2-celled, opening lengthwise, with the connective produced beyond the cells

Gynoecium

Ovary superior, sessile, 1-celled, with usually 3 parietal placentas each with one or more ovules; style usually simple

Fruits

Fruit an elastic loculicidal capsule, one- or more-seeded

Seeds

Seeds with fleshy endosperm and central mostly straight embryo