Pétiole

Publié vendredi 24 octobre 2014 Commenter 38
Feuille d'automne

Sommaire

Le pétiole, ou « petit pied » en latin, est un organe végétal situé entre le limbe d’une feuille et la tige.

Structure du pétiole

Interface d’échange de la sève

C’est une partie foliaire, essentiellement constituée de vaisseaux qui conduisent la sève dans le limbe et le reste de la plante.

La sève circule dans les deux sens dans le pétiole :

  • Du limbe vers le reste de la plante pour une alimentation en énergie créée par les cellules de la feuille par la photosynthèse.
  • Du reste de la plante vers le limbe, pour une alimentation de la feuille en minéraux captés par exemple au niveau des racines.

Devis Entretien de jardin
3 devis gratuits de pro en 48h, service gratuit et sans engagement
Demandez 3 devis gratuits

Solidité du pétiole

C’est une partie qui nécessite d’être très résistante pour pouvoir porter la feuille c'est-à-dire l'organe vitale pour une plante. Chez les plantes pluriannuelles, telles que les arbustes et les arbres, les feuilles doivent être maintenues pendant une à plusieurs années d’affilées. Les pétioles sont alors fortement solidifiés par un tissu de soutien : le collenchyme. Ce tissu se place sous l’épiderme du pétiole et autour des vaisseaux conducteurs. Ce sont des cellules vivantes qui confèrent au pétiole une résistance à la flexion et à la traction.

Formes du pétiole

Il est classiquement cylindrique, fin, court et vert ou brun. Cependant, il peut adopter beaucoup d’autres formes, et même d’autres fonctions. Sa longueur, sa largeur, sa couleur, mais aussi sa forme peuvent varier:

  • Pétioles charnus: Par exemple, le pétiole de la rhubarbe, de la blette ou du cardon, est très long et charnu. Celui-ci peut alors avoir une valeur économique par son intérêt culinaire, car il se commercialise pour l’alimentation humaine.
  • Pétiole-feuille: Le pétiole peut aussi prendre la forme et la fonction d’un limbe. Il peut alors le substituer partiellement ou complètement. Dans ce cas, on ne parle plus de pétiole mais de phyllode.
  • Absence de pétiole: Enfin, la plupart des feuilles possèdent un pétiole mais certaines exceptions n’en ont pas. Elles sont alors qualifiées de « sessile ».

A l’automne : mécanisme de la chute des feuilles

A l’automne, c’est un mécanisme au niveau du pétiole qui engendre la perte des feuilles des arbres caduques. En effet, les jours moins longs et les nuits plus froides sont le signal pour l’arbre que l’automne arrive. Tous les éléments nutritifs et énergétiques stockés dans les feuilles sont évacués dans le reste de la plante et le pétiole modifie sa structure pour se préparer à une abscission. L’abscission est la préparation d’un bouchon cicatriciel créé par des cellules qui se désintègrent à la base du pétiole. La feuille, ne pouvant plus échangée avec le reste de l’arbre, meurt, d’où le changement de sa couleur. Enfin, elle tombe sous l’action de son propre poids. La cicatrice créée est imperméable aux pathogènes extérieurs, il n’y a pas de blessure sur le rameau. L’arbre, débarrassé de ses feuilles inutiles en hiver car trop fragiles face au froid, est prêt pour passer l’hiver.

Posez toutes vos questions sur cet article

Vous vous posez une question sur l'article "Pétiole". Posez la sur qrmaison.com, notre site communautaire sur les travaux, le jardinage et la décoration

Découvrez ces autres articles
Cornus Florida
Cornus florida
Une floraison d'intérêt pour un jardin d'exception ! Les cornouillers, appartenant à la... +
Sureau
Purin de sureau
Le purin est le résultat d’une macération ou d’une infusion de végétaux, plus ou... +
Pelouse en train d'être tondue
Pour avoir une belle pelouse…
Souvent nos pelouses sont difficiles à entretenir, surtout dans le sud de la France, à... +
Façade fleurie
Les plus belles fleurs grimpantes
Que serait un jardin sans hauteur ? A ce titre, les fleurs grimpantes sont d'une importance... +
Fleurs d'été
Les fleurs d'été : semis, plantation, floraison, entretien
L'été est la période la plus propice à l'épanouissement du jardin, et les fleurs sont... +
Clémentinier en fructification
Greffe du clémentinier
Pourquoi la greffe du clémentinier ? Commençons par un petit rappel pour ne pas... +
Réagissez à cette article
Commentaires
Apurva - il y a 243 jours
Particularly overwhelming article all information uncovers major as anyone would to be possible and clear. By rules of the maker for sharing this blog. Keep on posting.Agartala Escorts Escorts in Ajmer Akola Escorts Service Escorts Service in Ambattur Amravati Escorts Agency
Répondre
Apurva - il y a 243 jours
An especially tangling page I saw this sort of blog. I like your work. I like your chance out also.Thankful for sharing.Asansol Escorts Escorts in Belgaum Bellary Escorts Service Escorts Service in Bhagalpur Bhavnagar Escorts Agency
Répondre
Apurva - il y a 243 jours
Overpowering site. The maker depicts all focal concentrate completely. People can be sensible. Overpowering clarification of the article simple to understand.Keep postingBhilai Escorts Escorts in Bhilwara Bhiwandi Escorts Service Escorts Service in Bikaner Bokaro Escorts Agency
Répondre
Apurva - il y a 243 jours
This is particularly overwhelming. I'm totally absolutely especially really happy to the point that you have shared this central electronic diary post. Continue to postCuttack Escorts Escorts in Davanagere Dhule Escorts Service Escorts Service in Durgapur Erode Escorts Agency
Répondre
life link - il y a 181 jours
What a really awesome post this is. Truly, one of the best posts I've ever witnessed to see in my whole life. Wow, just keep it up. Scam Risk
Répondre
seo mind - il y a 181 jours
Thank you for the post. I will definitely comeback. Scam Risk
Répondre
life link - il y a 181 jours
This is an awesome motivating article.I am practically satisfied with your great work.You put truly extremely supportive data. Keep it up. Continue blogging. Hoping to perusing your next post Scam Risk
Répondre
seo King - il y a 181 jours
With so many books and articles coming up to give gateway to make-money-online field and confusing reader even more on the actual way of earning money, Scam Risk
Répondre
life link - il y a 181 jours
It is extremely nice to see the greatest details presented in an easy and understanding manner. Scam Risk
Répondre
life link - il y a 181 jours
It is extremely nice to see the greatest details presented in an easy and understanding manner. Scam Risk
Répondre
mrseo mrseo - il y a 181 jours
Admiring the time and effort you put into your blog and detailed information you offer!.. Scam Risk
Répondre
life link - il y a 181 jours
I’ve read some good stuff here. Definitely worth bookmarking for revisiting. I surprise how much effort you put to create such a great informative website. Scam Risk
Répondre
life link - il y a 181 jours
I’ve read some good stuff here. Definitely worth bookmarking for revisiting. I surprise how much effort you put to create such a great informative website. Scam Risk
Répondre
seo mind - il y a 181 jours
My friend mentioned to me your blog, so I thought I’d read it for myself. Very interesting insights, will be back for more! Scam Risk
Répondre
life link - il y a 181 jours
I read a article under the same title some time ago, but this articles quality is much, much better. How you do this.. Scam Risk
Répondre
seo mind - il y a 181 jours
A debt of gratitude is in order for the blog entry amigo! Keep them coming... Scam Risk
Répondre
poojasharmaji - il y a 146 jours
I uncommonly esteem your committed Aerocity Escort capacities as the post you circulated have a few unprecedented information which is exceptionally worthwhile for me.
Répondre
poojasharmaji - il y a 146 jours
I uncommonly esteem your committed Aerocity Escort capacities as the post you circulated have a few unprecedented information which is exceptionally worthwhile for me.
Répondre
poojasharmaji - il y a 146 jours
I uncommonly esteem your committed Aerocity Escort capacities as the post you circulated have a few unprecedented information which is exceptionally worthwhile for me.
Répondre
poojasharmaji - il y a 146 jours
I uncommonly esteem your committed Aerocity Escort capacities as the post you circulated have a few unprecedented information which is exceptionally worthwhile for me.
Répondre
poojasharmaji - il y a 146 jours
I uncommonly esteem your committed Aerocity Escort capacities as the post you circulated have a few unprecedented information which is exceptionally worthwhile for me.
Répondre
poojasharmaji - il y a 146 jours
I uncommonly esteem your committed Aerocity Escort capacities as the post you circulated have a few unprecedented information which is exceptionally worthwhile for me.
Répondre
Jaipur Escorts - il y a 141 jours
To ensure you have the time of your life, we offer some of the mostJaipur Escorts. Our escort service ensures that you will be able to create memories that will last forever with these lovely and knowledgeable women.
Répondre
Jaipur Escorts - il y a 141 jours
To ensure you have the time of your life, we offer some of the mostJaipur Escorts. Our escort service ensures that you will be able to create memories that will last forever with these lovely and knowledgeable women.
Répondre
Jaipur Escorts - il y a 141 jours
To ensure you have the time of your life, we offer some of the most Our escort service ensures that you will be able to create memories that will last forever with these lovely and knowledgeable women.
Répondre
Jaipur Escorts - il y a 141 jours
To ensure you have the time of your life, we offer some of the most Our escort service ensures that you will be able to create memories that will last forever with these lovely and knowledgeable women.
Répondre
Sital Agrwal - il y a 106 jours

My name is Sital Agarwal from Mumbai. I am 24 years old a Hot and Beautiful Mumbai Escort Girl. I am Working as a Escorts in Mumbai from last 5 Years  for extra money and pleasure. Contact Me if you want to have fun with Hot, Sexy and Open Minded escort in Mumbai.

Mumbai Escorts

Call Girls in Mumbai

Mumbai Escorts Service

Visit our Chennai Locations :-

Escort Service in Chennai

Call Girls in Chennai

 

Répondre
Sital Agrwal - il y a 106 jours

My name is Sital Agarwal from Mumbai. I am 24 years old a Hot and Beautiful Mumbai Escort Girl. I am Working as a Escorts in Mumbai from last 5 Years  for extra money and pleasure. Contact Me if you want to have fun with Hot, Sexy and Open Minded escort in Mumbai.

Mumbai Escorts

Call Girls in Mumbai

Mumbai Escorts Service

Visit our Chennai Locations :-

Escort Service in Chennai

Call Girls in Chennai

 

Répondre
Sital Agrwal - il y a 106 jours

My name is Sital Agarwal from Mumbai. I am 24 years old a Hot and Beautiful Mumbai Escort Girl. I am Working as a Escorts in Mumbai from last 5 Years  for extra money and pleasure. Contact Me if you want to have fun with Hot, Sexy and Open Minded escort in Mumbai.

Mumbai Escorts

Call Girls in Mumbai

i.html">Call Girls in Chennai

 

Répondre
Sital Agrwal - il y a 106 jours

My name is Sital Agarwal from Mumbai. I am 24 years old a Hot and Beautiful Mumbai Escort Girl. I am Working as a Escorts in Mumbai from last 5 Years  for extra money and pleasure. Contact Me if you want to have fun with Hot, Sexy and Open Minded escort in Mumbai.

Mumbai Escorts

Call Girls in Mumbai

i.html">Call Girls in Chennai

 

Répondre
Luxury Service - il y a 55 jours
Our Call Girls are one of the most premium elite companions on the globe and you can have an enjoyable and sexual experience with Hyderabad Escorts Service. You can take girls to your own destination and enjoy yourself with them. Here, you can find a lot of call girls Escort in Hyderabad who will help you explore every aspect of India and make your dreams come true. Our escort and models are always at your service 24hours a day. These Hyderabad Escort Service are well trained to take you to the climax of sexual pleasure and enjoyment. Escorts in Hyderabad always bring our service to your doorstep. Just put a call through to us and we will be right there at your service. We ensure that your privacy is secure with us. We provide a unique service that no other escort service can.
Répondre
Luxury Service - il y a 55 jours
Our Call Girls are one of the most premium elite companions on the globe and you can have an enjoyable and sexual experience with Hyderabad Escorts Service. You can take girls to your own destination and enjoy yourself with them. Here, you can find a lot of call girls Escort in Hyderabad who will help you explore every aspect of India and make your dreams come true. Our escort and models are always at your service 24hours a day. These Hyderabad Escort Service are well trained to take you to the climax of sexual pleasure and enjoyment. Escorts in Hyderabad always bring our service to your doorstep. Just put a call through to us and we will be right there at your service. We ensure that your privacy is secure with us. We provide a unique service that no other escort service can.
Répondre
tripathibhawna6 - il y a 30 jours

We all believe in the quality of everything, so when you choose a call girl to romance do you still look at the quality? Hello friend my name is Bhwna I am living in Jaipur for the last four years for my college studies and also to live my selected moments, I love to meet new people, talk to them, and spend time with them, I am a Jaipur escorts girls if you want to romance with us just visit our website- Jaipur escorts

Répondre
tripathibhawna6 - il y a 30 jours
We all believe in the quality of everything, so when you choose a call girl to romance do you still look at the quality? Hello friend my name is Bhwna I am living in Jaipur for the last four years for my college studies and also to live my selected moments, I love to meet new people, talk to them, and spend time with them, I am a Jaipur escorts girls if you want to romance with us just visit our website- Jaipur escorts

Répondre
Soniya Singh - il y a 20 jours
I am Soniya, 22 years old, beautiful, and sexy independent call girl in Jaipur. If you are looking for Jaipur call girls then i am the one here. I am an extremely hot, sexy, and charming princess. With me, there is no dull moment because I am fun to be with and will take you to the Apex of sexual pleasure you deserve. i am also available jaipur call girl cash payment mode.
Répondre
soniya - il y a 10 jours
Great news, holy messenger! I'm soniya, I'm heavenly escort model, pouring out done with need aerocity escorts || call girls paharganj sana || call girls in rohini || call girls south delhi meenu || mahipalpur escorts and energy. Enduring you like stimulating, fast, lovely and showed women, I'm the best choice. I might not grip at any point reach you, a versatile man to feel in me... Text me on WhatsApp and pick your most basic expanded lengths of life!
Répondre
Encyclopédie des plantes
Acacia Albizzia Althéa Arbousier Artichaut de laon Azalée du japon Bacopa Bambou non traçant Bidens Bouleau pleureur Brocoli chinois Cactus de Noël Calla Cardons Catalpa Cèdre du liban Chamaecyparis Ciboule de chine Ciste Combava Cornus florida Courgette jaune Cycas Cyprès de florence Cyprès de provence
Derniers Articles
Des questions sur vos travaux de jardinage?

Vous avez une question sur vos travaux de jardinage ? sur l'entretien d'une plante ? Posez-les sur qrmaison.com. La communauté vous répond rapidement avec précision.

Posez votre question