A creeper is a plant that grows along the ground, around another plant, or up a wall by means of extending stems or branches. Creepers are unable to support themselves and rely on external structures for vertical growth. Some common examples of creepers include ivy, vines, and sweet peas.
Creepers exhibit two main growth habits – prostrate and climbing. Prostrate creepers spread horizontally across surfaces, while climbing creepers use tendrils, twining stems, adhesive pads, or other means to clamber upwards. This distinction leads to an interesting question – can a creeper stand erect without external support?
What is a creeper?
Creepers, also known as creeping plants or creeping vines, are plants that grow horizontally along the ground or climb structures using stems or tendrils. They cannot stand erect or upright on their own due to their weak stems and inability to remain self-supporting.
Some key characteristics of creepers:
– Weak stems that cannot remain upright and need external support to grow vertically
– Long trailing stems that extend horizontally across the ground or other surfaces
– Climbing mechanisms like tendrils, twining stems, adhesive pads, or clasping roots to attach to structures
– Rapid growth and spreading across surfaces
Common examples of creepers:
| Type | Examples |
|---|---|
| Vines | Grapes, passion flower, kiwi, honeyvine |
| Ivies | English ivy, Swedish ivy, needlepoint ivy |
| Other herbs/flowers | Periwinkle, creeping phlox, sweet pea, morning glory |
Creepers can be annual or perennial plants and are found in diverse environments from forests to deserts. They play an important ecological role in soil stabilization, providing shelter and food for wildlife, and allowing upward growth of forest canopies.
Growth habits of creepers
Based on their growth patterns, creepers can be categorized into two main types:
Prostrate creepers
Prostrate creepers grow horizontally along surfaces without any vertical growth. They spread out across the ground and low-growing vegetation using trailing or creeping stems. Examples include creeping thyme, prostrate knotweed, and prostrate spurge.
Climbing creepers
Climbing creepers exhibit vertical growth by climbing external structures like trees, walls, fences etc. They use specialized clinging roots, tendrils, twining stems or leaf stalks to anchor themselves and climb upwards. Examples include vines, ivies, and climbing flowering plants like morning glory.
Climbing creepers can be further classified based on climbing mechanisms:
| Type | Climbing mechanism | Example |
|---|---|---|
| Twining climbers | Flexible stems twist around structures | Beans, morning glories |
| Tendril climbers | Use tendrils to cling onto supports | Grapevines, passion flowers |
| Root climbers | Use adventitious roots to cling onto surfaces | Ivy, trumpet vine |
| Scrambling climbers | Use thorns or bristles to lean on supports | Roses, raspberries, blackberries |
This classification shows the adaptations that allow creepers to exhibit climbing growth despite their inability to stand erect independently.
Why can’t creepers stand erect on their own?
There are some key reasons why creepers cannot remain upright without external support:
Weak stems
Creepers tend to have very slender, flexible stems that can trail along surfaces but cannot remain erect. The stem tissue lacks the structural strength or rigidity to overcome gravitational pull and keep the plant upright.
Rapid growth
Many creepers exhibit very rapid horizontal growth across surfaces. This is facilitated by weak stems that can extend quickly. The energy goes into horizontal spread rather than growth of a self-supporting structure.
Low biomass
Creepers produce relatively little woody tissue or biomass compared to self-supporting plants. With their limited biomass, creepers stems cannot achieve enough girth or structural reinforcement to bear their own weight upright.
Resource optimization
It is metabolically cheaper for creepers to grow horizontally rather than invest resources in vertical structures. Creeping allows them to efficiently access sunlight and cover larger areas rapidly.
Lack of structural tissues
Creepers often lack specialized cells like collenchyma and sclerenchyma that provide structural strength and rigidity. The absence of these mechanical tissues makes the stems too flexible and weak to stand erect.
Strategies used by creepers for vertical growth
Despite their inherent inability to achieve self-supported vertical growth, creepers have evolved some fascinating strategies to climb upwards using external structures:
Twining and tendrils
Twining stems and tendrils allow creepers to entangle themselves around supports like poles and branches. This provides a scaffold for upward growth without investment in rigid stems. Example: Beans
Adhesive pads and clasping roots
Specialized adhesive pads on tendrils or clasping roots allow creepers to glue themselves directly onto walls, tree trunks and other surfaces. This provides firm anchorage for vertical ascent. Example: English ivy.
Spines and bristles
Some creepers use bristles, spines or hooked thorns to grip onto bark, rocky surfaces or trellises. These provide support as well as protection from animals. Example: Roses, cucumbers.
Leaning and scrambling
Scrambling creepers use their flexible stems to lean on surrounding vegetation. As support plants grow taller, the creeper also achieves vertical growth. Example: Blackberries
Examples of creepers that appear to stand erect
There are a few examples of plants that appear like creepers but can remain freestanding under certain conditions:
Wisteria
Wisteria has twining stems and tendrils that allow it to climb supports and spread extensively as a vine. However, with adequate sunlight and in sheltered locations, wisteria can produce short, stout trunks that support its weight in an erect form.
Trumpet vine
Trumpet vine uses aerial roots to climb up surfaces. Under optimal growing conditions, it can remain freestanding by developing heavier stems and self-clinging roots that provide anchorage. But it still requires support to truly thrive.
Campsis radicans
Campsis radicans or trumpet creeper can cling and climb very tall structures. When grown in containers with optimal soil nutrition and sunlight, it can remain erect with a woody trunk, but usually still needs some support.
Bougainvillea
Bougainvillea produces sprawling, vining shoots that need trellises for support. However, with its thorns it can lean and scramble on other vegetation and remain freestanding under the right growing conditions.
Training creepers to stand erect
While creepers cannot remain self-supporting on their own, it is possible to artificially train some climbing creepers to grow upright with support techniques:
Using trellises
Trellises provide rigid vertical structures for creepers to cling onto and climb upwards. Over time, creepers like grapes can be trained into freestanding cordons or espaliers using trellising.
Providing poles
Poles act like artificial tree trunks for twining or tendrilling creepers. Creepers like beans and morning glory can be trained up poles and then be supported by the pole to stand erect.
Using frames
Frames made of wood or metal can provide rigid scaffolding for creepers. The vertical frames bear the weight of the plant while also directing upward growth.
Pruning and training
Judicious pruning not only stimulates upward growth but also removes trailing stems so the creeper invests energy into the main upright stems. These can then be tied onto supports.
Optimizing soil and light
With adequate water, nutrients and sunlight, some creeping plants can achieve enough biomass and stem thickness to partially bear their own weight for a short erect period.
Conclusion
Creepers are plants adapted for rapid horizontal growth and climbing with support, rather than standing erect independently. Their weak, flexible stems and lack of structural tissues make creepers unable to overcome gravitational forces and remain upright without external support. However, specialized climbing mechanisms allow them to ascend vertically by clinging onto structures. While artificial training can induce erect growth in some creepers, their self-supporting ability is very limited. Ultimately, the abundant advantages of the creeping and climbing growth form outweigh the costs of being unable to stand erect themselves for creepers.