Cecropiaceae

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Snake Wood Family

Pourouma bicolor Mart., a canopy tree in the Cecropiaceae. Note the irregular shape but very regular venation of the leaves. Un árbol del dosel. Note la forma irregular de las hojas, y el patrón muy regular de las venas.


Description: This family is sometimes included as a tribe of Moraceae (e.g. Gentry 1993), but more frequently treated at the family level (e.g. Gomez et al. 2004). Recent molecular phylogenies (Stevens 2005) have included Cecropiaceae in Urticaceae. Cecropiaceae have simple, alternate leaves, often palmately lobed, with very regularly spaced secondary veins and finely parallel tertiary veins. They generally have thick stems with yellowish-brown transparent latex, and large deciduous stipules. The genera at La Selva are easy to distinguish:

  • Coussapoa species are hemiepiphytes, always with simple, entire, unlobed leaves; generally found in old growth, hemiepiphyte.
  • Cecropia is a fast-growing genus of second growth and forest edges. Cecropia species are medium to large trees, with very large, palmate, peltate leaves (that is, the petiole attaches to a point in the middle of the leaf blade instead of at the edge). The trunks are often whitish, with large leaf scars. Many species harbor Azteca ants in their hollow stems.
  • Pourouma species are large trees, with leaves that vary from unlobed to deeply lobed, palmate but not peltate. The leaves are thicker and much more asperous than those of Cecropia. Pourouma is also slower-growing than Cecropia, and often persists in old-growth forest.

Economic uses: Native people in Central America and the Amazon traditionally used Pourouma leaves for sandpaper.


Descripción: Algunas autoridades consideran a las Cecropiaceas una tribu de las Moraceas (p. ej. Gentry 1993), pero usualmente se le considera una familia separada (p. ej. Gomez et al. 2004). El árbol filogenético más reciente (Stevens 2005) incluye la familia Cecropiaceae dentro de las Urticaceas. Las Cecropiaceas tienen hojas simples, alternas, frecuentemente con lóbulos palmados, con un patrón de las venas muy regular. Usualmente tienen tallos gruesos con savia transparente y amarillenta y estípulas grandes y deciduas. Es fácil distinguir los géneros en La Selva:

  • Coussapoa: hemiepífitas de bosque maduro, siempre con hojas simples, enteras, y sin lóbulos.
  • Cecropia: un género de árboles de bosques perturbados o de las márgenes de los ríos. Especies de Cecropia son árboles de mediana a gran altura, con hojas grandes, palmadas, y peltadas (es decir, el pecíolo se inserta dentro de la lámina en lugar de en la márgen de la lámina). Los troncos usualmente son blancuzcos, con cicatrices grandes provenientes de las hojas caídas. Muchas especies tienen tallos vacíos en donde habitan hormigas del género Azteca.
  • Pourouma: árboles grandes, con hojas que pueden variar de enteras a muy lobuladas o palmadas pero nunca peltadas. Las hojas son más gruesas y ásperas que las hojas de Cecropia. Pourouma es un género que no crece tan rápidamente, y muchas veces, a diferencia de Cecropia, se le encuentra en bosque maduro.

Usos económicos: Los indios centroamericanos y amazónicos tradicionalmente usaban las hojas de Pourouma como papel de lija.


Genera/species at La Selva: Cecropia (2), Coussapoa (2), Pourouma (2).


FIELD MARKS – all have a large terminal stipule that eventually falls and leaves behind an obvious scar.


Cecropia – simple, palmately lobed leaves (5-7 lobes), peltate insertion of petiole (at center of leaf like the handle on an umbrella), secondary veins parallel, tertiary veins parallel and wavy, large terminal stipule (brown) leaves behind a horizontal annular scar at each node, pendant catkin-like inflorescences, hollow trunk inhabited by Azteca ants, mullerian bodies at base of petiole provide food for ants.


Peltate leaves of Cecropia.
Cecropia showing brown stipules and annular scars.
Cecropia trunk with Azteca ants. The brown area below the petioles contain food bodies for the ants.
Cecropia trunk with entry hole leading to hollow stem.
Cecropia obtusifolia.
Cecropia insignis has large peltate leaves and distinctive annular scars at each node.
Azteca ant and glycogen-rich food bodies at the base of a Cecropia insignis leaf.
Catkin-like inflorescence of Cecropia obtusifolia.
Coussapoa nymphaeifolia with large simple ovate leaves and inclined stipule scars growing in the lab clearing.
Coussapoa nymphaeifolia with terminal conical stipule and inclined stipule scars characteristic of the genus.


Pourouma – simple, palmately lobed leaves in some species (P. bicolor) and ovate leaves in others (P. minor), petiole insertion is normal (NOT peltate – look carefully), leaf sand papery, annular stipule scar.


Comparison of palmately lobed leaves of Pourouma bicolor and ovate leaves of Pourouma minor. Note the point of insertion of the petiole on the lobed leaf.
Pourouma leaf showing characteristic parallel seconday veins with parallel wavy tertiary veins.


Coussapoa – simple, ovate leaf, stipule scar is at an incline.


Coussapoa villosa. Photo by R. Aguilar courtesy of La Flora Digital de la Selva.


Ecorefs:

  • Epperson, B.K, Alvarez-Buylla, E.R. 1997. Limited seed dispersal and genetic structure in life stages of Cecropia obtusifolia. Evolution 51: 275-282.
  • Alvarez-Buylla, E.R, Garay, A.A. 1994. Population genetic structure of Cecropia obtusifolia, a tropical pioneer tree species. Evolution 48: 437-453.


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