Lidyanne Yuriko Saleme Aona
Universidade Federal do Recôncavo da Bahia (UFRB), Brazil.
Aquatic, perennial, rooted herbs. Leaves simple, spirally arranged, flat, sessile, without a distinct sheath, lanceolate to linear or nearly filiform, apically bidentate. Flowers axillary, solitary on short pedicels, emergent, actinomorphic, perfect, hypogynous, trimerous, with distinct calyx and corolla; sepals 3, free, opposite, green, valvate to subvalvate; petals 3, free, white, imbricate, short-clawed; stamens 3, alternate with petals; filaments slender, glabrous; anthers basifixed, tetrasporangiate to bisporangiate, opening by apical pores or pore-like slits or sometimes by pores at end of a tubular apical appendage; ovary unilocular, composed of 3 united carpels, placentation parietal; style simple, terminal; stigma short capitate or slightly trifid; 6-30 ovules/carpel, bitegmic, tenuinucellate. Fruit a loculicidal capsule with 3 lines of dehiscence, each midway between a placenta; seeds ovoid to globose, striate.
Notes on delimitation
- Mayacaceae belongs within the Order Poales, but differ vegetatively from most of the other members of this order.
- Anthers in some species are monothecal, the nucellar epidermis is basally thickened and the outer layer of the endosperm has proteins.
- The inflorescence is sometimes described as being terminal, but the flowers of the Neotropical species studied seem to be axillary and associated with a broad, adaxial prophyll-like structure.
- However, given the association of Mayacaceae with families that have scapose inflorescences with involucral bracts, the inflorescence of Mayacaceae deserves re-examination.
Distribution in the Neotropics
- Mayaca Aubl. (ca. 10 spp., Central America to Paraguay).
Distinguishing characters (always present)
- Mayacaceae are small herbs of marshes looking rather like club-mosses.
- They have numerous spirally-arranged, apically-toothed leaves, borne scattered along the stem.
- Pink to white apparently axillary flowers.
- Clearly differentiated calyx and corolla.
Other important characters
Key differences from similar families
Differs from other aquatic plants such as:
- Pontederiaceae, which have inflated petioles and flowers arranged in dense inflorescences.
- Haemodoraceae, where the calyx and corolla are fused and septal nectaries present.
Number of genera
One Neotropical genus: Mayaca.
Useful tips for generic identification
- See family description.
Notable genera and distinguishing features
- Mayaca: anthers with slit or apical, poricidal dehiscence.
- Most species are native to Tropical and warm-temperate America.
- One species occurs in tropical West Africa.
Stevenson, D.W. 1998. Mayacaceae. In K. Kubitzki (ed.) The families and genera of vascular plants - Volume 4. Springer Verlag. Berlin, p. 294-296.
How to cite
Aona, L.Y.S. (2009). Neotropical Mayacaceae. In: Milliken, W., Klitgård, B. & Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics. http://www.kew.org/science/tropamerica/neotropikey/families/Mayacaceae.htm.