What an appropriate link! Thanks a lot Ushadi
-- Dr. Gurcharan Singh Retired Associate Professor SGTB Khalsa College, University of Delhi, Delhi-110007 Res: 932 Anand Kunj, Vikas Puri, New Delhi-110018. Phone: 011-25518297 Mob: 9810359089 http://www.gurcharanfamily.com/ http://people.du.ac.in/~singhg45/ On Sun, Mar 25, 2012 at 5:04 PM, ushadi Micromini <[email protected] > wrote: > oh forgot the URL: > It is at : http://www.uq.edu.au/_School_Science_Lessons/9.70.1.GIF > thanks > Usha di > > On Sun, Mar 25, 2012 at 5:03 PM, ushadi Micromini < > [email protected]> wrote: > >> Gurcharanji I found a univ of queensland teaching manual ... in it they >> describe exactly the two leaf types you just talked of... >> I am sending the url in for sake of sharing with other non-botanists like >> me and for sake of completion for archives... >> Thanks again >> Usha di >> ======== >> >> >> On Fri, Mar 23, 2012 at 11:44 AM, Gurcharan Singh <[email protected]>wrote: >> >>> Ushadi >>> There is a famous doctrine in Biology which all of us are familiar with >>> "Ontogeny Repeats Phyllogeny". The modified leaf of Australian Acacia >>> (Acacia auriculiformis) is derived from the normal bipinnate leaves so >>> common in other Acacia species. In this evolutionary modification the >>> pinnae got reduced and their function was taken up by the flattened petiole >>> (called Phyllode, as against phylloclade of Opuntia which is a modified >>> stem taking function of leaf) of the leaf in the adult plant. Hence it is >>> common to see juvenile plants with some pinnae at the tip of the phyllode, >>> and these eventually fall off. Adult trees are without these pinnae and >>> have only flattened phyllodes functioning as leaves. Of course every leaf >>> has to fall once it has become old: In evergreen trees they develop and >>> fall off periodically so that tree remains green throughout the year >>> (Mango, Alstonia, etc.); In deciduous trees on the other hand the fresh >>> leaves appear in spring (Late February-March-early April) and all fall off >>> in autumn so that tree remains naked for few months in winter (Prunus, >>> Pyrus, Salix, Populus). >>> Delhi (and perhaps some other warmer cities in India) don't have >>> typical four seasons. Here so called autumn is brief few days in March when >>> deciduous trees suddenly lose their leaves and fresh leaves come up after a >>> gap of few days, the Delhi Spring. >>> >>> I hope I have shared some helpful information. >>> >>> -- >>> Dr. Gurcharan Singh >>> Retired Associate Professor >>> SGTB Khalsa College, University of Delhi, Delhi-110007 >>> Res: 932 Anand Kunj, Vikas Puri, New Delhi-110018. >>> Phone: 011-25518297 Mob: 9810359089 >>> http://www.gurcharanfamily.com/ >>> http://people.du.ac.in/~singhg45/ >>> >>> >>> On Fri, Mar 23, 2012 at 10:44 AM, shrikant ingalhalikar < >>> [email protected]> wrote: >>> >>>> Dear Usha di, >>>> >>>> Wish you a happy Hindu New Year. Thank you very much for your >>>> curiosities, hope I satisfy them at least partially. >>>> >>>> This is my first attempt to handle the new format yet I believe that my >>>> post carries the name Acacia auriculiformis. Ironically the post itself >>>> became more intriguing than the leaves. Earleaf Acacia and Australian >>>> Acacia are more names to help you navigate with Google. Pardon me for >>>> defficient and confusing information. I am attaching another image to help >>>> you ID this invasive tree that has reached most of our wild habitats. >>>> >>>> I am also a pitiable non botanist like most of us. Please excuse me to >>>> have narrated in a style that disguises me to be a card carrying botanist. >>>> I take privilege of passing the batton of your queries to a person who >>>> carries the necessary stars and shoulder pips.With regards.Shrikant >>>> >>>> >>>> >>>> >>>> >>>> >>>> On Thursday, March 22, 2012 10:02:53 PM UTC+5:30, Ushadi wrote: >>>> >>>>> BUT I am still ignorant of the tree's ID and >>>>> what happens when that flat "leaf " falls off, does it mean that the >>>>> small leaves on its apex fall off too? >>>>> so some leaves have pinnae and some donot? as in this pic... >>>>> >>>>> if I knew the name , I could google it... >>>>> then I would not have to bother you... >>>>> >>>>> but all this discussion without a name, assumes that most of the 1900 >>>>> members are all botanists... REMEMBER ONLY A HANDFUL ARE CARD CARRYING >>>>> BOTANISTS>> THE REST OF US are NON BOTANISTS.... so please take pity on >>>>> us .... >>>>> >>>>> thanks >>>>> Usha di >>>>> ==== >>>>> >>>>> >>>>> >>>>> On Thu, Mar 22, 2012 at 8:30 PM, Satish Phadke >>>>> <[email protected]>wrote: >>>>> >>>>>> Very good illustration. >>>>>> >>>>>> On Thu, Mar 22, 2012 at 7:20 PM, shrikant ingalhalikar < >>>>>> [email protected]> wrote: >>>>>> >>>>>>> This common exotic tree is seen with only falcategreen veinless >>>>>>> phyllodes whichdisguise like simple leaves. Like most Acacias this >>>>>>> should >>>>>>> havebeen havingbi-pinnate leaves. Interestingly this Acacia too has >>>>>>> bipinnate leaves but they are seen only in sapling stage. Pinnae2, 2-5 >>>>>>> cm, >>>>>>> deciduous; leafletsopposite, 6-10, sessile, oblong, 5-8 mm; petiole 5-8 >>>>>>> mm, >>>>>>> modifying and elongating to a phyllode 10-15 cm long. Scar of fallen >>>>>>> pinnae >>>>>>> can be seen at the rounded apex of the phyllode. Regards, Shrikant >>>>>>> Ingalhalikar >>>>>>> >>>>>> >>>>>> >>>>>> >>>>>> -- >>>>>> Dr Satish Phadke >>>>>> >>>>> >>>>> >>>>> >>>>> -- >>>>> Usha di >>>>> =========== >>>>> >>>>> >>> >>> >>> -- >>> Dr. Gurcharan Singh >>> Retired Associate Professor >>> SGTB Khalsa College, University of Delhi, Delhi-110007 >>> Res: 932 Anand Kunj, Vikas Puri, New Delhi-110018. >>> Phone: 011-25518297 Mob: 9810359089 >>> http://www.gurcharanfamily.com/ >>> http://people.du.ac.in/~singhg45/ >>> >>> >> >> >> -- >> Usha di >> =========== >> >> > > > -- > Usha di > =========== > >
