... wow dear Pankaj .. whatever you have put, must be a deep subject ... but I could read it fearlessly !! Many many thanks for the efforts. Regards Dinesh.
On Tue, Feb 15, 2011 at 1:38 PM, Pankaj Kumar <sahanipan...@gmail.com>wrote: > Dear Dinesh sir, > > Based on molecular analysis as well as morphological differences, by > the top experts of the world, the order LILIALES was broken down into > three > > Liliales > Asparagales > Diosocoreales > > Asparagales included many of the families, like Orchidaceae, > Boryaceae, Blandfordiaceae, Lanariaceae, Asteliaceae, Hypoxidaceae, > Ixioliriaceae, Tecophilaeaceae, Doryanthaceae, Iridaceae, > Xeronemataceae, Xanthorrhoeaceae sensu lato, Hemerocallidoideae, > Xanthorrhoeoideae, Asphodeloideae, Amaryllidaceae sensu lato, > Agapanthoideae, Allioideae, Amaryllidoideae and Asparagaceae sensu > lato. > > Asparagaceae inturn was divided into sub families which included many > of the earlier families such as > > subfamily Agavoideae = family Agavaceae and family Hesperocallidaceae > subfamily Aphyllanthoideae = family Aphyllanthaceae > subfamily Asparagoideae = family Asparagaceae sensu stricto > subfamily Brodiaeoideae = family Themidaceae > subfamily Lomandroideae = family Laxmanniaceae > subfamily Nolinoideae = family Ruscaceae > subfamily Scilloideae = family Hyacinthaceae > > Cordyline belonged Laxmanniaceae which is not under Asparagaceae where > as Dracaena belonged to Ruscaceae and earlier Ruscaceae did belong to > Liliaceae but that was loooooong time back and not any more. > > Some of the basis differences are provided in Wikipedia which are given > below. > > ASPARAGALES: > > The order is clearly circumscribed on the basis of DNA sequence > analysis, but is difficult to define morphologically, since its > members are structurally diverse. Thus although most species in the > order are herbaceous, some no more than 15 cm high, there are a number > of climbers (e.g. some species of Asparagus), as well as several > genera forming trees (e.g. Agave, Cordyline, Yucca, Dracaena), some of > which can exceed 10 m in height. Succulent genera occur in several > families (e.g. Aloe). > > One of the defining characteristics of the order is the presence of > phytomelan, a black pigment present in the seed coat, creating a dark > crust. Phytomelan is found in most families of the Asparagales > (although not in Orchidaceae, thought to be a sister to the rest of > the group). > > Almost all species have a tight cluster of leaves (a rosette), either > at the base of the plant or at the end of a more-or-less woody stem; > the leaves are less often produced along the stem. The flowers are in > the main not particularly distinctive, being of a general 'lily type', > with six tepals, either free or fused from the base. > > The order is thought to have first diverged from other related > monocots some 120-130 million years ago (early in the Cretaceous > period), although given the difficulty in classifying the families > involved, estimates are likely to be uncertain. > > LILIALES: > > This order consists mostly of herbaceous plants, but lianas and shrubs > occur. They are mostly perennial plants, with food storage organs such > as corms or rhizomes. The family Corsiaceae is notable for being > heterotrophs. > > The order has worldwide distribution. The larger families (with more > than 100 species) are roughly confined to the Northern Hemisphere, or > are distributed worldwide, centering on the north. On the other hand, > the smaller families (with up to 10 species) are confined to the > Southern Hemisphere, or sometimes just to Australia or South America. > The total number of species in the order is now about 1300. > > One big question raised by someone was, why Dracaena or Cordyline is > in Asparagaceae and not Liliaceae. > Answer is because NEITHER OF THEM HAVE CORM OR BULB. > > Classifications change from time to time. When Linne wrote Species > Plantarum, he had his limitations in describing a taxa, he didnt have > much facility and hence if you see his descriptions, trust me, half of > the plant a common man wont be able to identify. For example, he > described two taxa as > > Dioscorea alata: follis cordatis, caule alato bulifero > Dioscorea bulbifera: follis cordatis, caule laevi bulbifero > > Linne didnt have a proper microscope. But then things improvised and > more and more technology got involved and people started describing > species in more details and then finally is the age of DNA which some > Indians have just started using. Though world has reached PROTEONOMICS > which India is still unaware of. > > -- > *********************************************** > "TAXONOMISTS GETTING EXTINCT AND SPECIES DATA DEFICIENT !!" > > > Pankaj Kumar Ph.D. (Orchidaceae) > Research Associate > Greater Kailash Sacred Landscape Project > Department of Habitat Ecology > Wildlife Institute of India > Post Box # 18 > Dehradun - 248001, India >
