Eriocaulaceae Martinov

Milliken, W., Klitgard, B. and Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics. http://creativecommons.org/licenses/by/3.0

Morphology General Habit

Herbs annual or perennial, aquatic or terrestrial; rhizome vertical or horizontal or corm, covered by remaining leaf sheaths, with axillary trichomes, and glabrous to hirsute roots; aerial stems, if present, branched or not

Morphology Leaves

Leaves in rosette, rarely distributed along the stem, generally spirally arranged, rarely spiro- distichous , spiro-tritichouso or pseudo- verticillate simple, lanceolate to linear, membranaceous to coriaceous, fenestrated or not, with expanded sheaths or not; scapes terminal or axillary, generally surrounded by a cylindrical spathe with apex truncated or acute

Morphology Reproductive morphology Inflorescences

Inflorescence capitulum with many sterile involucral bracts

Morphology Reproductive morphology Flowers

Pistillate flowers with superior ovary, 2-3-locular, ovules 1 per locule, basal placentation; styles 2-3 fused, stigmatic portions completely fused or not, with nectariferous portions or not, with staminodes or not Staminate flowers with 2-4 or 6 stamens, filament free, cylindrical or flattened, anthers 2-sporangiate or 4-sporangiate, dehiscing by longitudinal slits, dorsifixed or basifixed, with pistillodes Flowers small, about 2 or 4 mm long generally pedicellate, unisexual, with staminodes or pistillodes or rarely hermaphrodite, generally more than 50 per capitula, with centripetal formation, with bracts or not; dichlamydeous, actinomorphic or zygomorphic; sepals 3-2, free or rarely fused; petals 3-2, rarely reduced to a hairy lobe, free or fused, with glands or not, with anthophore or not

Morphology Reproductive morphology Fruits

Fruit dehiscent capsule or rarely indehiscent achene; pericarp membranaceous; seeds 1 per locule, rarely reduced to 1 per fruit, seed coat reticulate, striate, rough or smooth, embryo not differentiated, endosperm amilaceous.

Note

Notes on delimitation: Close to Xyridaceae and Mayacaceae, it is currently placed within the order Poales (APG II, 2003). Number of genera: Eriocaulaceae comprises 9 genera with ca. 850 spp. in Neotropics. Actinocephalus - 31 spp. Blastocaulon - 5 spp. Eriocaulon - ca. 60 spp. Leiothrix - ca. 50 spp. Paepalanthus - ca. 500 spp. Philodice - 2 spp. Rondonanthus - 6 spp. Syngonanthus - ca. 200 spp. Tonina - 1 sp. "Although Eriocaulaceae can be easily recognized among the other Monocotyledons by possessing small flowers arranged in dense capitula, identifying the genera and the species is not a simple task. The genera are usually defined by floral characteristics that are difficult to see in the field. Species identification is also not simple for several reasons. The habit and indumentum play a central role, but can vary according to the environment. The last revision for the whole family was carried out by Ruhland (1903) and needs to be revised. In addition, Silveira (1908, 1928) published 183 species without any key, and Harold Moldenke published dozens of species, also without any key. Some species have considerable economic importance in Brazil, especially those of the genus Syngonanthus. The scapes and inflorescences of these species are collected and dried in the sun, to be sold as ornamental objects and often exported from Brazil to different countries as ""everlasting plants"". Some species in the states of Bahia, Minas Gerais, and Tocantins are critically endangered due to over-exploitation (Giulietti et al. 1988, 1996; Schmidt et al. 2007). Phylogenetic studies (Andrade 2007, Unwin 2004) suggest that some modifications in the family taxonomy should be done. Blastocaulon emerges as polyphyletic and should be merged within Paepalanthus. Philodice clusters within species of Syngonanthus, and in this case, a proposal to conserve the name Syngonanthus against Philodice, and its synonymisation would be relevant. Two sections of Syngonanthus form a well supported clade segregated from the rest of the genera, and the re-establishment of Comanthera L.B.Sm.to congregate these species is regarded."

Distribution

Eriocaulaceae are widely distributed in the Neotropics. Species occur in different habitats, but most of them are distributed in the Brazilian campo rupestre vegetation, in the Venezuelan Tepuis, and in the Brazilian cerrado (savanna). Actinocephalus (Bong.) Sano - Endemic, restricted to Brazil. Blastocaulon Ruhland - Endemic, restricted to Espinhaço Range, Brazil. Eriocaulon L. - Pantropical, widely distributed in Neotropics. Leiothrix Ruhland - Endemic, restricted to South America. Paepalanthus Mart. - Widely distributed in Neotropics, few species in Africa. Philodice Mart. - Endemic, tropical South America. Rondonanthus Herzog - Endemic, restricted to Tepuis Highlands in Venezuela, Guyana and Brazil. Syngonanthus Ruhland - Widely distributed in Neotropics, few species in Africa. Tonina Aubl. - Endemic, widely distributed in tropical Central and South America. Actinocephalus - Native, endemic. Blastocaulon - Native, endemic. Eriocaulon - Native. Leiothrix - Native, endemic. Paepalanthus - Native. Philodice - Native, endemic. Rondonanthus - Native, endemic. Syngonanthus - Native. Tonina - Native, endemic.

Diagnostic

Key differences from similar families: Differs from Xyridaceae and Mayacaceae by small unisexual flowers, inflorescence arranged in dense capitula, and spiraperturate pollen grains. Leaves arranged in a basalrosette. Capitula subtended by a scape, which is surrounded by a spathe. Spiraperturate pollen grains. Distinguishing characters (always present): Eriocaulaceae are easily recognized by possessing unisexual flowers grouped in a dense capitulum. Except Actinocephalus and Eriocaulon that can be easily recognized in the field, all other genera are exclusively defined by a few floral characters, which are better observed under a stereomicroscope. Key to the genera of Neotropical Eriocaulaceae 1. Fenestrated leaves; flowers diplostemonous; petals glandular.... Eriocaulon 1. Non-fenestrated leaves; isostemonous flowers; petals eglandular .... 2 2. Pistillate flowers with linear staminodes or complete stamens .... Rondonanthus 2. Pistillate flowers with scale-like staminodes .... 3 3. Style with stigmatic and nectariferous portions separating at different levels .... Leiothrix 3. Style with stigmatic and nectariferous portions separating at same level.... 4 4. Pistillate flowers with petals reduced to a hairy lobe .... Tonina 4. Pistillate flowers with conspicuous petals .... 5 5. Pistillate flowers with petals fused at middle .... 65. Pistillate flowers with petals free.... 7 6. Anthers 2-sporangiate .... Philodice 6. Anthers 4-sporangiate .... Syngonanthus 7. Umbellate inflorescence in paracladial axis.... Actinocephalus 7. Paracladial axis absent.... 8 8. Anthers 2-sporangiate.... Blastocaulon 8. Anthers 4-sporangiate.... Paepalanthus Actinocephalus - umbellate inflorescences in paracladial axis, trimerous flowers, and completely fused stigmatic portions. Eriocaulon - fenestrated leaves, diplostemonous flowers, and glandular petals. Leiothrix- pistillate flowers with free petals, style branching at different levels, 4-sporangiate anthers, and seed coat striate. Paepalanthus - pistillate flowers with free petals, style branching at the same level, and 4-sporangiate anthers. Syngonanthus - pistillate flowers with fused petals, style branching at the same level, and 4-sporangiate anthers.

Eriocaulaceae, R.D. Meikle. Flora of West Tropical Africa 3:1. 1968

Morphology General Habit

Annuals or perennials; stems often very short, occasionally elongate; leaves narrow, often crowded or rosulate, frequently with large, conspicuous cells

Morphology Reproductive morphology Inflorescences

Inflorescence an involucrate capitulum comprising numerous small, densely crowded flowers often subtended by floral bracts; peduncle leafless, unbranched, usually arising from a well-developed basal sheath; flowers unisexual, the males and females mixed in the same capitulum, or the males in the middle and the females around, or rarely males and females in separate capitula; perianth membranous or scarious, the segments usually in 2 distinct series, the outer segments ("sepals") generally free in female flowers, often connate in male, the inner ("petals") free or rarely connate in female flowers, connate and often very reduced in male flowers

Morphology Reproductive morphology Flowers Androecium

Stamens equal in number to, or twice as many as the inner perianth segments; anthers 2-thecous, or less often 1-thecous, introrse

Morphology Reproductive morphology Flowers Gynoecium

Ovary 2-3-locular, ovules solitary, pendulous in each loculus; style usually distinct, divided above into 2-3 elongate, simple (or occasionally bifid) stigmas, sometimes with alternating appendages

Morphology Reproductive morphology Fruits

Fruit a membranous loculicidal capsule; seeds relatively large, testa generally scabrid or papillose; endosperm copious