Our navigation bar is loading . . . . . .


Advertise on JCSM - Hear JCSM's Weekly Devotions via Podcast/RSS Feed! - Skip These Ads

You can advertise your site right here!Click here to learn more!

 10,000 Wise Quotes and Spiritual Sayings by Jason Gastrich, Ph.D.

 JCSM's Top 1000 Christian Sites - Free Traffic Sharing Service! Join the Online Christ-Centered Ministries!

-
Jesus Christ Saves Ministries

Click here and add this page to your favorites!

Return to the JCSM Study Center!

Encyclopedia Britannica



GERANIACEAE

This article appears in Volume V11, Page 763 of the Encyclopedia Britannica.

Encyclopedia Britannica - Main :: GEO-GNU
GERANIACEAE , in botany, a small but very widely distributed natural order of Dicotyledons belonging to the subclass Polypetalae, containing about 36o species in 11 genera. It is re-presented in Britain by two genera, Geranium (crane's-bill) and Erodium (stork's-bill), to which belong nearly two-thirds of the total number of species. The plants are mostly herbs, rarely becoming shrubby, with generally simple glandular hairs on the stem and leaves. The opposite or alternate leaves have a pair of small stipules at the base of the stalk and a palminerved blade. The
flowers
 , which are generally arranged in a cymose inflorescence, are hermaphrodite, hypogynous, and, except in Pelargonium, regular. The parts are arranged in
fives
 . There are five free sepals, overlapping in the bud, and, alternating with these, five free petals. In Pelargonium the flower is zygomorphic , with a spurred posterior sepal and the petals differing in size or shape. In Geranium the stamens are obdiplostemonous, i.e. an outer whorl of five opposite the petals alternates with an inner whorl of five opposite the sepals; at the base of each of the antisepalous stamens is a honey-gland. In Erodium the members of the outer whorl are reduced to scale-like structures (staminodes), and in Pelargonium from two to seven only are fertile. There is no satisfactory explanation of this break inthe regular alternation of successive whorls; the outer whorl of stamens arises in course of development before the inner, so that there is no question of subsequent displacement. There are five, or sometimes fewer, carpels, which unite to form an ovary with as many chambers, in each of which are one or two, rarely more, pendulous anatropous ovules, attached to the central column in such a way that the micropyle points outwards and the raphe is turned towards the
placenta
 . The long beak-like style divides at the top into a corresponding number of slender stigmas.
The larger-flowered species of Geranium are markedly protandrous, the outer stamens, inner stamens and stigmas becoming functional in succession. For instance, in meadow crane's-bill G. pratense, each whorl of stamens ripens in turn, becoming erect and shedding their
pollen
 ; as the anthers wither the filaments bend outwards, and when all the anthers have diverged the stigmas become mature and ready for pollination. By this
Meadow Crane's-bill, Geranium pratense. Flora Londinensis.)
1, Flower after removal of petals. 3, Floral diagram, the dots
2, Fruit after splitting. 1 and 2 opposite the inner stamens
about natural size. represent honey-glands. arrangement self-pollination is prevented and cross-pollination ensured by the visits of bees which come for the honey secreted by the glands at the base of the inner stamens.
In species with smaller and less conspicuous
flowers
 , such as G. molle, the flowers of which are only a to % in. in
diameter
 , self-pollination is rendered possible, since the divisions of the stigma begin to
separate
  before the outer stamens have shed all their
pollen
 ; the nearness of the stigmas to the dehiscing anthers favours self-pollination.
In the ripe fruit ,the carpels
separate
  into five one-seeded portions (cocci), which break away from the central column, either rolling elastically outwards and upwards or becoming spirally twisted. In most species of Geranium the cocci split open on the inside and the seeds are shot out by the elastic uptwisting (fig. 1); in Erodium and Pelargonium each coccus remains closed, and the long twisted upper portion separates from the central column, forming an awn, the distribution of which is favoured by the presence of bristles or hairs. The embryo generally fills the seed, and the cotyledons are rolled or folded on each other.
(After
Curtis
 ,
Geranium is the most widely distributed genus; it has 16o species and is spread over all temperate regions with a few
species in the tropics. Three British speciesG. sylvaticum,
G. pratense and G. Robertianum (herb-Robert)reach the
arctic zone, while G. patagonicum and G. magellanicum are
found in the antarctic. Erodium contains 50 species (three are British), most of which are confined to the Mediterranean region and west Asia, though others occur in America, in
South
  Africa and West Australia. Pelargonium, with 195 species, has its centre in
South
  Africa; the well-known garden and green-
house
  " geraniums " are species of Pelargonium (see GERANIUM).


End of Article: GERANIACEAE


If you wish, you can link directly to this article.
<a href="http://jcsm.org/StudyCenter/Encyclopedia/GEO_GNU/GERANIACEAE.html">
GERANIACEAE
</a>
(Previous)
GERALDTON 		(Next)
GERANIUM

 


 

Jesus Christ Saves Ministries

The JCSM Study CenterAmerica's Christian FoundationSkeptic's Annotated Bible: Corrected and ExplainedNKJV Web Hosting and Services
JCSM's Sermons, Debates and the Bible on MP3The Online Christ-Centered MinistriesDo You Have A Web Site?  Your Ad Could Be Here!Seminary Notes and PapersThe Picturesque Photo Albums


Jesus Christ Saves Ministries, P.O. Box 70696, Pasadena, CA 91117

JCSM is a 501(c)(3), non-profit organization. Copyright © 1997-present.


Kingdom Debt Solutions - Be Debt Free! Sport Logos - Quality Athletic Equipment The JCSM Study Center Your Ad Could Be Here! Launch A Successful Internet Organization or Business! Learn Guitar, Bass, or Piano in San Diego county!

You can advertise your site right here!

Free & Cheap Cell Phones  |  Cheap Long Distance Phone Service Carriers  |  Talk America Local Phone Service  |  Ztel & MCI - Unlimited Long Distance
Compare Cell Phone Plans & Companies  |  International Calling Cards & Prepaid Phone Cards  |  Voice Over IP Broadband Internet Phone Service  |  Wireless Phone Plans & Cheap Cell Phones

Dr. Jason Gastrich

Jason Gastrich, Ph.D.

 

Jesus Christ Saves Ministries is directed by Dr. Jason Gastrich.  It was founded in 1997 and it exists to bring people into a life-changing and productive relationship with Jesus Christ.  JCSM offers over 200,000 free web pages, discussion boards, weekly html and mp3 devotionals, free email accounts, and much more.

Jesus Christ Saves Ministries
P.O. Box 9297
San Diego, CA  92169
1-877-850-3878 or Email

JCSM is a 501(c)(3), non-profit organization. Copyright © 1997-2008.

_____________________________________________________________________________

Online First Aid and CPR Certification  .  The Online Christ Centered Ministries  .  The Skeptic's Annotated Bible: Corrected and Explained  .  The Inerrancy Discussion Board  .  Free Email Accounts  .  Home Equity Loans  .  JasonGastrich.com  .  The Missions, Apologetics, and Creation Bible Conference  .  Young Earth Creation Science  .  San Diego Music Lessons  .  10,000 Wise Quotes and Spiritual Sayings  .  Gastrich.net  .  Maximizing the Internet: 12 Keys to Success  .  Louisiana Baptist University  .  NKJV Web Hosting and Services  .  Michael Newdow  .  San Diego Soccer Training  . Christian Guitar Lessons  .  Jesus Christ Saves Ministries  .  Eternal Security