Hydathode


Hydathode

A hydathode is a type of secretory tissue in leaves, usually of Angiosperms, that secretes water through pores in the epidermis or margin of leaves, typically at the tip of a marginal tooth or serration. They probably evolved from modified stomata. It is involved in guttation, where water is released from the top in order to transport the nutrients in the water from the roots to the leaves. Hydathodes are connected to the plant vascular system by a vascular bundle.

Since the liquid being extruded is from the xylem it also contains salts, sugars, and organic compounds dissolved in water and this is sometimes seen to crystalize on evaporation, forming a white powdery substance on the leafs edge. This crystallisation is very obvious in halophytes, plants adapted to live in high salt environments, and consequently the hydathodes are known as salt glands in those species.

See also

*Transpiration
*Xylem
*Vascular plants

External links

* [http://www.sbs.utexas.edu/mauseth/weblab/webchap9secretory/9.3-10.htm hydathode physiology]


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Hydathode —   [griechisch] die, / n, Wasserspalte, meist umgewandelte Spaltöffnung im Hautgewebe der Blätter vieler Pflanzen, durch die Wasser austritt (Guttation). * * * Hy|da|tho|de, die; , n <meist Pl.> [zu griech. hodós = Weg] (Bot.): Öffnung im… …   Universal-Lexikon

  • hydathode — [hī′də thōd΄] n. [Ger < Gr hydōr (gen. hydatos), WATER + hodos, way: see ODE1] a specialized microscopic pore or stoma on the leaves of many plants, through which water may be excreted …   English World dictionary

  • hydathode — /huy deuh thohd /, n. Bot. a specialized leaf structure through which water is exuded. [ < G Hydathode (1894) < Gk hydat , s. of hýdor water + hodós way, path; cf. ODE2, CATHODE] * * * …   Universalium

  • hydathode — hy•da•thode [[t]ˈhaɪ dəˌθoʊd[/t]] n. bot a specialized leaf structure through which water is exuded • Etymology: < G Hydathode (1894) < Gk hydat , s. of hýdōr water +hodós way, path; cf. ode II …   From formal English to slang

  • hydathode — noun Etymology: International Scientific Vocabulary, from Greek hydat , hydōr water + hodos road Date: 1895 a specialized pore on the leaves of higher plants that functions in the exudation of water …   New Collegiate Dictionary

  • Hydathode — Guttation an einem Erdbeer Blatt Hydathoden oder Wasserspalten sind eine spezielle Form wasserabscheidender Drüsen, die bei zahlreichen Pflanzen vorkommen (Einkeimblättrige und Zweikeimblättrige). Durch sie kann auch bei sehr hoher Luftfeuchte… …   Deutsch Wikipedia

  • hydathode — noun A tissue, in the leaves of many plants, that contains microscopic pores through which water is excreted …   Wiktionary

  • Hydathode — Les hydatodes sont des orifices aménagés entre des cellules épidermiques foliaires, par lesquels l eau issue d un parenchyme aquifère ou d un vaisseau de xylème peut être rejetée[1]. Ces pores opèrent notamment lors du phénomène de guttation par… …   Wikipédia en Français

  • Hydathode — Hy|da|tho|de die; , n (meist Plur.) <zu ↑hydato... u. 1↑...ode> Blattöffnung bei Pflanzen zur Abgabe von Wasser (Bot.) …   Das große Fremdwörterbuch

  • hydathode — [ hʌɪdəθəʊd] noun Botany a modified pore, especially on a leaf, which exudes drops of water. Origin C19: from Gk hudōr, hudat water + hodos way …   English new terms dictionary