Introduction

TERMINOLOGY

Lianas (also known as vines, climbing plants or climbers) are plants with long, flexible, climbing stems that are rooted in the ground, and usually have long dangling branches. In order to climb, they have developed a wide range of climbing strategies and specialized structures affix themselves to the supporting structures. In addition, their woods usually present a wide range of distinctive anatomical structures. Trees and shrubs on the other hand, are distinguished by their self-supporting, rigid, erect, stems. However, the distinction between climbing and self-supporting plants is often blurred by the occurrence of plants with long, semi-rigid stems that arch or lean over other plants. These less efficient climbers are known as clambering, scrambling or scandent plants. The definition of a climbing plant is also obscured by the presence of species that become epiphytes after their climbing stems loose connection with the ground, or by epiphytes that establish contact with the ground by producing long stems or roots that climb down. In this project we have adopted a more comprehensive definition of a climber, so that we include plants with well-defined climbing mechanisms as well as scandent and leaning plants. Our definition exclude creepers or plants with long, flexible stems that lay on the ground without climbing, our treatment include only climbers that reach more than 2 m in length. Lianas can reach 165m in Rattan palms, and 30-40 cm diameter in Malpighiaceae and in some Fabaceae (Schenella).

Other terms synonymous with climbing plants

lianas – woody climbers with stems reaching more than 10 m in length. 
vine, bejuco [Spanish], cipó, trepadeira, corda, icipó [Portuguese] – a general term for climbing plants but often used for herbaceous or slightly woody climbers, the word bejuco is synonymous with liana in many Spanish speaking countries in the Americas.
twiners, voluble, enredadera [Spanish] -  a climber with twining stems such as in family Convolvulaceae and Malpighiaceae
ascending, scandent, leaning, sarmentoso [Spanish] – a vague term that refers to climbers with no specialized climbing mechanism.
ropes, sogas [Spanish] – vague term that often refers to lianas or woody climbers.

GENERAL CHARACTERISTICS OF CLIMBERS

1. Long, flexible stems with abundance of soft tissue that allow for rapid growth, and vegetative regeneration.
2. Extremely efficient vascular system specialized in water conduction and lacking internal structural support. Xylem vessels often are wide and long and have elevated hydraulic conductivities.
3. Distinctive cambial activity resulting in stems with complex tissue arrangements as seen in transversal sections of stems.
4. Specialized climbing mechanisms

LIANA DIVERSITY IN THE NEOTROPICS

(Native or naturalized species)
119 Families/977 genera/10966 species 
Pteridophytes: 10 families/18 genera/29 species: scandent or root-climbers
Gymnosperm: 1 family; 1 genus’/8 taxa: twiners
Monocots: 12 families/59 genera/1214 species: twiners, scandent, root-climbers, and tendrilled
Magnolids:  7 families/13 genera/350 species
Eudicots: 81 families/970 genera/9400 species

MOST SPECIES DIVERSE FAMILIES IN THE NEOTROPICS
(with total number of species)

Apocynaceae 1318 
Fabaceae 1011 
Asteraceae 873 
Malpighiaceae 635
Sapindaceae 512
Convolvulaceae 485
Passifloraceae 483
Bignoniaceae 433
Cucurbitaceae 366
Rubiaceae 285
Solanaceae 224
Euphorbiaceae 198
Menispermaceae 191
Melastomataceae 168
Celastraceae 141
Acanthaceae 123
Ericaceae 118
Gesneriaceae 114
Marcgraviaceae 114
Dilleniaceae 112
Vitaceae 105
Polygalaceae 98

MOST SPECIES DIVERSE GENERA IN THE NEOTROPICS
          (with total number of species)

Passiflora 475
Mikania 333
Dioscorea 286
Ipomoea 268
Serjania 250
Philodendron 228
Paullinia 218
Matelea 210
Aristolochia 195
Heteropterys 131
Mandevilla 119
Pentacalia 113
Smilax 112
Solanum 111
Stigmaphyllon 99
Bomarea 95
Anthurium 95
Ditassa 94
Manettia 94
Marsdenia 93
Dalechampia 92