Dendrocnide moroides - Gympie gympie Stinging Tree

Dendrocnide moroides, also known as the Gympie Gympie, moonlighter, or stinger, is a large shrub native to rainforest areas in northeastern Australia, the Moluccas and Indonesia. It is best known for stinging hairs which cover the whole plant and deliver a potent neurotoxin when touched. It is the most virulent species of stinging tree.
D. moroides usually grows as a single-stemmed plant reaching 1–2 metres in height. It has large, heart-shaped leaves that are about 12–22 cm long and 11–18 cm wide, with finely toothed margins.


Ecology
The species is unique in the genus in having bisexual inflorescences in which the few male flowers are surrounded by female flowers. The flowers are small, and once pollinated the stalk swells to form the fruit. Fruits are juicy and mulberry-like and are bright pink to purple. Each fruit contains a single seed which is on the outside of the fruit.
The species is an early coloniser in rainforest gaps; seeds germinate in full sunlight after soil disturbance. Although relatively common in Queensland, the species is uncommon in its southern-most range, and is listed as an endangered species in New South Wales.
The giant stinging tree and the shining-leaved stinging tree are other large nettles occurring in Australia.

Toxicity
Contact with the leaves or twigs causes the hollow silica-tipped hairs to penetrate the skin. The sting causes a painful stinging sensation which can last for days or even months, and the injured area becomes covered with small red spots joining together to form a red, swollen mass. The sting is known to be potent enough to kill humans, and it can also kill dogs and horses. However the sting does not stop several small marsupial species, including the Red-legged Pademelon, insects and birds from eating the leaves. Some research has been done on the composition of the neurotoxin; however, the exact composition and method of action for the toxin remains unknown.

source:http://en.wikipedia.org/wiki/Dendrocnide_moroides

Hatred Towards the Teachers

Guys, apa yang terlintas dalam pikiran kalian ketika mendengar kata 'guru'? Sosok yang menyebalkan, si gudang PR, orang yang pelit nilai, atau bahkan orang yang kalian kagumi? Guru adalah orang yang memberikan pengajaran terhadap suatu ilmu di dalam suatu organisasi yang kita kenal dengan sekolah. Dalam kehidupan sehari-hari tentunya kita tidak pernah terlepas dari sekolah. Otomatis kita juga tidak akan pernah terlepas dari ajaran seorang guru.

Dalam era globalisasi ini, guru sangat berperan penting dalam upaya memeberikan pendidikan yang maksimal terhadap anak-anak. Namun jika diperhatikan, dalam era ini juga banyak terdapat anak-anak yang jika boleh dibilang kurang mampu untuk berprestasi dengan baik. Apakah ini ada kaitannya dengan cara si guru menerangkan materi pelajaran? Ataukah mungkin juga hal ini juga ada kaitannya dengan cara belajar si anak tersebut?

Seringkali dapat kita jumpai dalam kehidupan sehari-hari. Banyak anak remaja yang sering mendapat masalah dari guru dalam suatu mata pelajaran tertentu. Misalnya mendapat teguran, dimarahi, atau bahkan mendapatkan perlakuan yang kasar. Biasanya setelah mendapat hukuman seperti itu, sering muncul pemikiran bahwa sang guru tersebut tidak dapat mengajar dengan baik. Hal ini cenderung menyebabkan sang anak menjadi tidak suka dan membenci sang guru tersebut. Hal yang lebih parah adalah anak tersebut akan cenderung melawan guru dan bahkan mengadu domba dengan orang tunya. Tapi apakah pemikiran anak tersebut benar?

Jika boleh menjawab, saya akan menjawab tidak. Mengapa harus tidak? Karena pemikiran seperti itu memang salah untuk ditafsirkan. Kegagalan seperti ini bukan disebabkan oleh faktor guru yang mengajar, melainkan disebabkan oleh diri anak tersebut. Anak tersebut sering mendapat hukuman di kelasnya memang karena anak tersebut sering melakukan tindakan yang seharusnya tidak dilakukan ketika belajar, seperti tidur, melakukan kegiatan yang lain, atau bahkan mengganggu konsentrasi teman yang benar-benar ingin belajar.

Ada 3 hal yang penting untuk diperhatikan, yakni:
- Jangan mudah terpengaruh, bila ada seorang teman yang mengajakmu untuk membuat
onar di kelas, katakan tidak untuk itu dan berusahalah untuk membuat temanmu
terpengaruh oleh hal baik yang kita lakukan
- Berusaha membuat suasana belajar yang nyaman, suasana belajar yang nyaman tentunya
akan menggugah minat belajar siswa. Namun suasana kelas yang berisik dan liar tidak
akan membuat suasana belajar dikelas menjadi nyaman
- Jadilah diri sendiri, teruslah lakukan tindakan yang menurut kamu baik untuk di-
lakukan saat belajar di kelas. Jangan melakukan perbuatan yang dapat membuat teman
dan guru menjadi jengkel saat masuk ke kelas.

Semoga dengan adanya artikel ini, kita dapat saling membangun dan meningkatkan kualitas belajar antar pelajar di seluruh sekolah di Indonesia, sekian dan terimakasih.
GBu guys :)

oleh: Samdaniel Sutanto

AL4Y

Bagaimana semestinya kita dengan tepat menanggapi keberadaan 'alay'

Apa itu 'alay'? Kata ini sedang populer di tengah masyarakat, khususnya di dunia remaja. Berdasarkan penelusuran, berikut adalah sedikit gambaran apa itu alay dari dunia maya yang mencoba mendokumentasikan berbagai gagasan tentang alay salah satunya dari sebuah blog. "Seseorang yang memakai baju yang tidak wajar, seperti celana skinny, dan berpenampilan yang menurut orang-orang itu "NORAK", rambut yang norak, pokoknya gayanya gak trendy banget deh, gak gaul. Dan kalo SMS itu bahasanya susah dibaca".

Cara bagaimana mereka bersikap dan bertingkah laku pun ternyata bisa menjadi rujukan identitas seorang alay. Masih dari sumber yang sama, remaja-remaja alay ini sering bergaya sok kaya, sok imut, sok cantik, sok keren, sok gaul, sok techno, dan gemar berfoto narsis. Nama-nama di situs tersebut yang disinyalir sebagai alay kerap ditemui jika namanya juga terkesan narsis dan banyak ditambahkan huruf 's' atau 'z'. jika terdapat nama seperti 'pRinceSscuTez' atau model yang serupa, orang inilah yang diberi predikat alay.

Jika seseorang sampai pada tahap kesimpulan bahwa individu berpredikat alay, salah satu sebabnya dapat ditilik dari rentang usia mereka, yakni 11 sampai 21 tahun. Memang pada rentang usia ini para remaja sedang berusaha mencari identitas diri. Di samping itu, remaja-remaja ini juga cenderung memiliki keingintahuan yang besar akan berbagai hal yang dianggap unik, baru, keren, tetapi tidak dicerna lebih dulu sebelum diserap ke dalam keseharian mereka.

Bisa dibilang eksistensi alay memang tidak bisa dipungkiri. Mungkin saja orang-orang yang berpredikat alay ada disekitar kita. Kalau sudah begitu, apa yang sebaiknya dilakukan? Berikut ini hal yang penting untuk disimak.

Konfusius pernah berkata "Jangan melakukan sesuatu kepada sesama yang kamu tidak ingin orang lain lakukan kepadamu". Ternyata ucapannya masih sangat relevan, bahkan sampai sekarang. Hendaknya seorang remaja tidak mencela akan adanya fenomena alay. Tidak ada orang di dunia ini yang senang dicela orang lain 'kan?

Terakhir adalah pilihan tindakan yang paling penting, yang sebagaimana dituturkan oleh orang bijak sebagai diam itu emas. Alay adalah hal yang salah atau benar, itu bergantung pada penilaian tiap individu. Jadi daripada berkomentar pedas, menyindir, mencela, tidakkah lebih baik diam? Lagipula kehadiran mereka tidak merugikan kita 'kan?

Kuman di seberang lautan tampak, gajah di pelupuk mata tidak tampak. Peribahasa tadi menekankan introspeksi yang merupakan hal mendasar untuk bertindak tepat. Mengapa? Adalah hal yang tak dapat dipungkiri bahwa di dunia ini tidak ada seseorang yang sempurna. Pandangan soal benar-salah pun sangat subjektif untuk kasus ini.

Maka dari itu daripada mencela orang lain, tidakkah jauh lebih baik untuk melihat diri sendiri, apakah diri sendiri sudah benar? Seorang alay bisa saja dihubungkan sebagai individu yang gemar berpakaian berlebihan, tetapi lihatlah diri sendiri, apakah berpakaian ke tempat ibadah dengan bercelana pendek dan sandal adalah pilihan busana yang tepat?

Introspeksilah, apakah diri sendiri sudah benar? Menghakimi seseorang memang sangat mudah, tapi apakah diri sendiri sudah yakin benar, tidaklah mudah.

Sumber:

Best Teens NO.1 THN.I Edisi Januari - Februari 2011
oleh: Yonathan Oktavianus

Poison Ivy - Toxicodendron radicans

Toxicodendron radicans, better known as poison ivy (older synonyms are Rhus toxicodendron and Rhus radicans), is a poisonous North American plant that is well known for its production of urushiol, a clear liquid compound found within the sap of the plant that causes an itching rash in most people who touch it. The plant is not a true ivy (Hedera).

Poison ivy can be found growing in any of the following three forms:

- as a trailing vine that is 10–25 centimeters tall (4 to 10 inches)

- as a shrub up to 1.2 meters tall (4 feet)

- as a climbing vine that grows on trees or some other support

Distribution and habitat

Poison ivy grows throughout much of North America, including the Canadian Maritime provinces, Quebec, Ontario, Manitoba, and all U.S. states east of the Rockies, as well as in the mountainous areas of Mexico up to around 1,500 m (4,900 ft) (caquistle or caxuistle is the Nahuatl term), and is normally found in wooded areas, especially along edge areas. It also grows in exposed rocky areas and in open fields and disturbed areas. It also grows as a forest understory plant, although it is only somewhat shade tolerant. The plant is extremely common in suburban and exurban areas of New England, the Mid-Atlantic, and southeastern United States. Similar species, poison oak, and Toxicodendron rydbergii are found in western North America. Poison ivy rarely grows at altitudes above 1,500 m (4,900 ft), although the altitude limit varies in different locations. The plants can grow as a shrub up to about 1.2 metres (3.9 ft) tall, as a groundcover 10–25 cm (3.9–9.8 in) high, or as a climbing vine on various supports. Older vines on substantial supports send out lateral branches that may at first be mistaken for tree limbs.

It is not particularly sensitive to soil moisture, although it does not grow in desert or arid conditions. It grows in a wide variety of soil types, and soil pH from 6.0 (acidic) to 7.9 (moderately alkaline). It can grow in areas subject to seasonal flooding or brackish water.

It is more common now than when Europeans first entered North America. Real estate development adjacent to wild, undeveloped land has engendered "edge effects," enabling poison ivy to form vast, lush colonies in such places. It is listed as a noxious weed in the U.S. states of Minnesota and Michigan and the Canadian province of Ontario.

Poison ivy and its relatives are virtually unknown in Europe.

Description

The deciduous leaves of poison ivy are trifoliate with three almond-shaped leaflets. Leaf colour ranges from light green (usually the younger leaves) to dark green (mature leaves), turning bright red in fall; though other sources say leaves are reddish when expanding, turn green through maturity, then back to red, orange, or yellow in the fall. The leaflets of mature leaves are somewhat shiny. The leaflets are 3 to 12 cm long, rarely up to 30 cm. Each leaflet has a few or no teeth along its edge, and the leaf surface is smooth. Leaflet clusters are alternate on the vine, and the plant has no thorns. Vines growing on the trunk of a tree become firmly attached through numerous aerial rootlets. The vines develop adventitious roots, or the plant can spread from rhizomes or root crowns. The milky sap of poison ivy darkens after exposure to the air.

Poison ivy spreads either vegetatively or sexually. Poison ivy is dioecious; flowering occurs from May to July. The yellowish- or greenish-white flowers are typically inconspicuous and are located in clusters up to 8 cm above the leaves. The berry-like fruit, a drupe, mature by August to November with a grayish-white colour. Fruits are a favourite winter food of some birds and other animals. Seeds are spread mainly by animals and remain viable after passing through the digestive tract.

Aids to identification

The following three characteristics are sufficient to identify poison ivy in most situations: (a) clusters of three leaflets, (b) alternate leaf arrangement, and (c) lack of thorns. Although a number of other plants fit this simplified description, any plant with these criteria should be prudently avoided by people unfamiliar with identifying poison ivy. Identification by experienced people is often made difficult by leaf damage, leafless conditions during winter, and unusual growth forms due to environmental and/or genetic factors. The appearance of poison ivy can vary greatly between environments and even individual specimens within a single area.

Various mnemonic rhymes describe the characteristic appearance of poison ivy:

- Leaves of three, let it be.

- Hairy vine, no friend of mine. Poison ivy vines are very poisonous.

- Raggy rope, don't be a dope! Poison ivy vines on trees have a furry "raggy" appearance. This rhyme warns tree climbers to be wary. Old, mature vines on tree trunks can be quite large and long, with the recognizable leaves obscured among the higher foliage of the tree.

- One, two, three? Don't touch me.

- Berries white, run in fright and Berries white, danger in sight."

- Longer middle stem, stay away from them. This refers to the middle leaflet having a notably longer stem than the two side leaflets and is a key to differentiating it from the similar-looking Rhus aromatica - Fragrant sumac.

- Red leaflets in the spring, it's a dangerous thing. This refers to the red appearance that new leaflets sometimes have in the spring. (Note that later, in the summer, the leaflets are green, making them more difficult to distinguish from other plants, while in autumn they can be reddish-orange.)

- Side leaflets like mittens, will itch like the dickens. This refers to the appearance of some, but not all, poison ivy leaves, where each of the two side leaflets has a small notch that makes the leaflet look like a mitten with a "thumb." (Note that this rhyme should not be misinterpreted to mean that only the side leaflets will cause itching, since actually all parts of the plant can cause itching.)

- If butterflies land there, don't put your hand there. This refers to the fact that some butterflies land on poison ivy, since they are not affected, which provides them protection as their predators avoid eating the plant.

- If it's got hair, it won't be fair. This refers to the hair that can be on the stem and leaves of poison ivy.

Effects on the body

The reaction caused by poison ivy, urushiol-induced contact dermatitis, is an allergic reaction. Around 15% to 30%of people have no allergic response, but most people will become sensitized with repeated or more concentrated exposure to urushiol. Reactions can progress to anaphylaxis. Over 350,000 people are affected by poison ivy annually.

The pentadecylcatechols of the oleoresin within the sap of poison-ivy and related plants causes the allergic reaction; the plants produce a mixture of pentadecylcatechols, which collectively is called urushiol. After injury, the sap leaks to the surface of the plant where the urushiol becomes a blackish lacquer after contact with oxygen.

Urushiol binds to the skin on contact, where it causes severe itching that develops into reddish coloured inflammation or non-coloured bumps, and then blistering. These lesions may be treated with Calamine lotion, Burow's solution compresses or baths to relieve discomfort, though recent studies have shown some traditional medicines to be ineffective. Over-the-counter products to ease itching—or simply oatmeal baths and baking soda—are now recommended by dermatologists for the treatment of poison ivy.

The oozing fluids released by scratching blisters do not spread the poison. The appearance of a spreading rash indicates that some areas received more of the poison and reacted sooner than other areas or that contamination is still occurring from contact with objects to which the original poison was spread. The blisters and oozing result from blood vessels that develop gaps and leak fluid through the skin; if the skin is cooled, the vessels constrict and leak less. If poison ivy is burned and the smoke then inhaled, this rash will appear on the lining of the lungs, causing extreme pain and possibly fatal respiratory difficulty. If poison ivy is eaten, the mucus lining of the mouth and digestive tract can be damaged. A poison ivy rash usually develops within a week of exposure and can last anywhere from one to four weeks, depending on severity and treatment. In rare cases, poison ivy reactions may require hospitalization.

Urushiol oil can remain active for several years, so handling dead leaves or vines can cause a reaction. In addition, oil transferred from the plant to other objects (such as pet fur) can cause the rash if it comes into contact with the skin. Clothing, tools, and other objects that have been exposed to the oil should be washed to prevent further transmission.

People who are sensitive to poison ivy can also experience a similar rash from mangoes. Mangoes are in the same family (Anacardiaceae) as poison ivy; the sap of the mango tree and skin of mangoes has a chemical compound similar to urushiol. A related allergenic compound is present in the raw shells of cashews. Similar reactions have been reported occasionally from contact with the related Fragrant Sumac (Rhus aromatica) or Japanese lacquer tree.

Similar-looking plants

• Virgin's Bower (Clematis virginiana) (also known as Devil's Darning Needles, Devil's Hair, Love Vine, Traveller's Joy, Virginia Virgin's Bower, Wild Hops, and Woodbine; syn. Clematis virginiana L. var. missouriensis (Rydb.) Palmer & Steyermark ) is a vine of the Ranunculaceae family native to the United States. This plant is a vine which can climb up to 10–20 ft tall. It grows on the edges of the woods, moist slopes, fence rows, in thickets and in streambanks. It produces white, fragrant flowers about an inch in diameter between July and September.

• Box-elder (Acer negundo) saplings have leaves that can look very similar to those of poison ivy, although the symmetry of the plant itself is very different. While box-elders often have five or seven leaflets, three leaflets are also common, especially on smaller saplings. The two can be differentiated by observing the placement of the leaves where the leaf stalk meets the main branch (where the three leaflets are attached). Poison ivy has alternate leaves, which means the three-leaflet leaves alternate along the main branch. The maple (which the box-elder is a type of) has opposite leaves; another leaf stalk directly on the opposite side is characteristic of box-elder.

• Virginia creeper (Parthenocissus quinquefolia) vines can look like poison ivy. The younger leaves can consist of three leaflets but have a few more serrations along the leaf edge, and the leaf surface is somewhat wrinkled. However, most Virginia creeper leaves have five leaflets. Virginia creeper and poison ivy very often grow together, even on the same tree. Be aware that even those who do not get an allergic reaction to poison ivy may be allergic to the oxalate crystals in Virginia creeper sap.

• Western Poison-oak (Toxicodendron diversilobum‎) leaflets also come in threes on the end of a stem, but each leaflet is shaped somewhat like an oak leaf. Western Poison-oak only grows in the western United States and Canada, although many people will refer to poison ivy as poison-oak. This is because poison ivy will grow in either the ivy-like form or the brushy oak-like form depending on the moisture and brightness of its environment. The ivy form likes shady areas with only a little sun, tends to climb the trunks of trees, and can spread rapidly along the ground.

• Poison Sumac (Toxicodendron vernix) has compound leaves with 7–15 leaflets. Poison sumac never has only three leaflets.

• Kudzu (Pueraria lobata) is a non-toxic edible vine that scrambles extensively over lower vegetation or grows high into trees. Kudzu is an invasive species in the southern United States. Like poison ivy it has three leaflets, but the leaflets are bigger than those of poison ivy and are pubescent underneath with hairy margins.

• Blackberries and raspberries (Rubus spp.) can resemble poison ivy, with which they may share territory; however, blackberries and raspberries almost always have thorns on their stems, whereas poison ivy stems are smooth. Also, the three-leaflet pattern of some blackberry and raspberry leaves changes as the plant grows: leaves produced later in the season have five leaflets rather than three. Blackberries and raspberries have many fine teeth along the leaf edge, the top surface of their leaves is very wrinkled where the veins are, and the bottom of the leaves is light minty-greenish white. Poison ivy is all green. The stem of poison ivy is brown and cylindrical, while blackberry and raspberry stems can be green, can be squared in cross-section, and can have prickles. Raspberries and blackberries are never truly vines; that is, they do not attach to trees to support their stems.

• The thick vines of Riverbank Grape (Vitis riparia), with no rootlets visible, differ from the vines of poison ivy, which have so many rootlets that the stem going up a tree looks furry. Riverbank grape vines are purplish in colour, tend to hang away from their support trees, and have shreddy bark; poison ivy vines are brown, attached to their support trees, and do not have shreddy bark.
• Fragrant Sumac (Rhus aromatica) has a very similar appearance to poison ivy. While both species have three leaflets, the center leaflet of poison ivy is on a long stalk, while the center leaflet of fragrant sumac does not have an obvious stalk. When crushed, fragrant sumac leaves have a fragrance similar to citrus while poison ivy has little or no distinct fragrance. Fragrant sumac produces flowers before the leaves in the spring, while poison ivy produces flowers after the leaves emerge. Flowers and fruits of fragrant sumac are at the end of the stem, but occur along the middle of the stem of poison ivy. Fragrant sumac fruit ripens to a deep reddish color and is covered with tiny hairs while poison ivy fruit is smooth and ripens to a whitish color.

sumber : http://en.wikipedia.org/wiki/Toxicodendron_radicans