Marcgraviaceae Bercht. & J.Presl

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

Terrestrial, hemiepiphytic or epiphytic lianas or shrubs, rarely small trees

Morphology Roots

Roots sometimes adventitious

Morphology General Glands

Hypophyllous glands on the lower surface of the leaf blade, raphide cells and variously shaped sclereids frequent

Morphology Leaves

Leaves simple, alternate, exstipulate, glabrous, margins entire or minutely crenate

Morphology Reproductive morphology Inflorescences

Inflorescences terminal, racemose, sometimes pseudo-umbels or pseudo-spikes, erect or pendulous

Morphology Reproductive morphology Inflorescences Bracts

Bracts transformed into variously shaped nectaries

Morphology Reproductive morphology Flowers

Flowers bisexual, actinomorphic, hypogynous, 2-bracteolate, the bracteoles sepaloid or deltoid, sometimes lacking

Morphology Reproductive morphology Flowers Calyx

Sepals 4-5, unequal, free or nearly so, imbricate, persistent

Morphology Reproductive morphology Flowers Corolla

Petals 3-5, imbricate, free or connate

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 3 to many; filaments free or basally connate, uniseriate; anthers basifixed or nearly so, dithecal, tetrasporangiate, introrse, longitudinally dehiscent

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary superior, completely or incompletely 2-20-locular; ovules numerous

Morphology Reproductive morphology Fruits

Fruits subglobose, apiculate with a persistent style and stigma, capsular, loculicidally and septifragously dehiscent from the base (sometimes appearing berry -like), pulpy inside

Morphology Reproductive morphology Seeds

Seeds hemispherical to reniform, few to numerous with a shiny reticulate testa.

Diagnostic

Usually climbing. Often hemiepiphytic- Youngest leaf enclosing the terminalbud. Young growth often reddish coloured by anthocyanins. Flowers with variously connate petals. Stamens 3 or 5 or many. Distinguishing characters (always present): Woody plants. Bracts with extrafloral nectaries adapted into variously shaped nectar -containers. Terminal inflorescences: racemes, umbels or spikes. Leaves alternate and simple with abaxialglands. Fruit capsular with seeds embedded in fleshy pulp. Notable genera and distinguishing features: See first image: inflorescence structure. Key to genera of the Neotropical Marcgraviaceae  1. Inflorescence umbellate or subumbellate ... 21. Inflorescence spicate or racemose ... 3 2. Inflorescence completely fertile; sepals and petals 5; petals free or variously connate; leaves spirally arranged ... Marcgraviastrum 2. Inflorescence partly sterile (central flowers aborted with only the bracteal nectaries developed); sepals and petals 4; petals calyptrately connate; leaves distichously arranged ... Marcgravia 3. Inflorescence spicate; nectaries attached to the rachis next to the flowers ... Sarcopera 3. Inflorescence racemose; nectaries variously attached to the pedicel... 4 4. Stamens 3-5, rarely 4 or 6-8; nectaries attached to the pedicel at the base of the calyx, rarely at some distance ... 54. Stamens (5-)12-35(-80); nectaries attached to the pedicel at various distances from the calyx, but never at its base ... 6 5. Ovary 2-locular; nectaries gibbose or somewhat leaf-like, solid or nearly so ... Ruyschia 5. Ovary 3-5-locular; nectaries tubular, hollow, often auriculate... Souroubea 6. Inflorescence an elongated raceme, 25-60(-85) cm; pedicels 2-5(-7) mm; nectaries adnate above the middle of the pedicel, never attached at the base ... Norantea 6. Inflorescence a short raceme, 4-25(-35) cm; pedicels (20-)30-70 mm; nectaries adnate below the middle of the pedicel, rarely at the base ... Schwartzia

Distribution

Native and endemic to the Neotropics, Norantea guianensis sometimes cultivated in countries outside its range (e.g. Jamaica, Costa Rica, Trinidad). Marcgravia (ca. 65 spp.): S Mexico, Mesoamerica, South America, Antilles. Marcgraviastrum (15 spp.): S Nicaragua to Peru, Bolivia plus 2 spp. in E Brazil. Norantea (2 spp.): Caribbean and Amazonian basin of NE South America. Ruyschia Jacq. (9 spp.): Mesoamerica, N Andes, Lesser Antilles. Sarcopera (ca. 10 spp.): Honduras to N Bolivia, Guyayana Highlands. Schwartzia Vell. (ca. 15 spp.): Costa Rica through the Andes south to Bolivia, in the Caribbean basin and 1 sp. in E Brazil. Souroubea (19 spp.): Mexico to Bolivia (absent from the Antilles). The Marcgraviaceae are endemic to the Neotropics.  Species range from Southern Mexico to Northern Bolivia and Eastern Brazil including the Antillean arc. Marcgraviastrum (Wittm. ex Szyszyl.) de Roon & S.Dressler, Souroubea Aubl., Norantea Aubl. and Sarcopera Bedell are missing in the Antilles (although Norantea guianensis Aubl. is rarely cultivated as an ornamental). Taxa are mostly found in primary humid tropical lowland forests or montane rain or cloud forests.

Note

The elaborate inflorescences with the variously shaped bracteal “nectary -containers” are frequented by a wide range of visitors (insects, lizards, birds, bats, non-flying mammals). Different pollination syndromes are exemplified in the various taxa. Whereas Ruyschia and Souroubea seem predominantly insect-pollinated (flies?, butterflies, hawk-moths?), Norantea, Sarcopera and Schwartzia brasiliensis (Choisy) Bedell ex Gir.-Cañas are probably best adapted to bird-pollination, especially by perching birds. Sarcopera sessiliflora (Triana & Planch.) Bedell was the first plant where pollen transmission by birds' feet was described. Most Schwartzia, Marcgraviastrum and Marcgravia spp. seem to be primarily bat-pollinated, but the ornithophilous syndrome seems to occur as well. This is a coarse generalisation and surprisingly many Marcgraviaceae are probably autogamous as well (and even cleistogamous, as experimentally proven in Marcgravia coriacea Vahl). The brightly coloured pulp with the small seeds exposed when the capsules split open suggest endozoochorous dispersal. Apart from occasional horticultural use in the tropics the family has no significant economic value. Two subfamilies: Marcgravioideae: leaves distichous; conspicuous heterophylly between juvenile, plagiotropous and adult orthotropous branches; perianth tetramerous, petals fully fused to form a caducous cap; only central (sterile) flowers of inflorescence fused with nectarybract, other flowers lacking nectary (Marcgravia L.). Noranteoideae: leaves spiral; perianth usually pentamerous, petals distinct to somewhat fused; each flower usually subtended by nectarybract  (all other genera). Vegetatively similar to the Ternstroemiaceae (non-climbing!) this family was formerly considered to be close to Theaceae/Ternstroemiaceae. Recent molecular data associate it rather with Balsaminaceae, and the former Theaceae-satellites Pellicieraceae and Tetrameristaceae. "Number of genera: Seven genera (see ""Distribution in the Neotropics"")."