PDA

View Full Version : Dragons breath Roots?


Harth23
08/24/2016, 08:42 PM
I was at a LFS. Today and they told me dragons breath usually grows roots. I have never personally seen it with roots and have a bunch of it with no roots. Is the guy misinformed or am I doing something wrong with mine that it does not grow roots.

farfromsea
08/25/2016, 01:25 AM
Looking around it seems that dragon's breath is classified as protists and thus since they have no vascular system like "traditional' plants they do not have roots.

This is unlike Caulerpa sp., however, who obviously have little rhizoids underneath and are classified as plants. Not sure on the dragon's breath though. Curious for the answer

JZinCO
08/25/2016, 09:58 AM
I was at a LFS. Today and they told me dragons breath usually grows roots. I have never personally seen it with roots and have a bunch of it with no roots. Is the guy misinformed or am I doing something wrong with mine that it does not grow roots.

Technically you're both wrong ;) Algae do not have roots ( https://depts.washington.edu/fhl/mb/mbhome/glossary.html ). Dragon's breath (Halymenia durvillei) does have a holdfast.

Looking around it seems that dragon's breath is classified as protists and thus since they have no vascular system like "traditional' plants they do not have roots.

This is unlike Caulerpa sp., however, who obviously have little rhizoids underneath and are classified as plants. Not sure on the dragon's breath though. Curious for the answer
Some correction. Classifications such as protist are about as useful as saying bryophytes. These informal terms only tell you what an organism is not but say little about what an organism is.
Generally speaking, Caulerpa spp. are little different in anatomy than from Halymenia spp. The primary difference is the holdfast and rhizoid. Caulerpa spp. are not plants. They do not have specialized tissue (e.g. the cambium which provides for vascular transport).

sources: UW Friday Harbor Lab glossary https://depts.washington.edu/fhl/mb/mbhome/glossary.html
slideshow on basics of algae http://www.slideshare.net/rituparnakalita1/algae-14613341
De Smedt et al (2001) Nova Hedwigia 73:3-4
Sealife base entry on Halymenia durvillei
http://www.sealifebase.org/summary/Halymenia-durvillei.html

JZinCO
08/25/2016, 10:01 AM
Woops. I mis-wrote. The primary difference between Caulerpa and Halymenia is the prescence of a rhizoid in the former.
If you want to see a picture of the inconspicious holdfast on Halymenia see this link and go to Fig 41D (headsup, it is a pdf)
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwj5193Q6dzOAhUM0WMKHWJDBucQFggcMAA&url=http%3A%2F%2Fwww.abctaxa.be%2Fvolumes%2Fvolume-6-sri-lankan-seaweeds-methodologies-and%2FABC_TAXA_6_HIGH_RES_Part4.pdf%2Fdownload%2Fen%2F1%2FABC%2520TAXA%25206_HIGH%2520RES_Part4.pdf&usg=AFQjCNGTqMIGiDgVGskAmHK_72TX1LX3wg

A little more information. Rhizoids and holdfasts function as a way to support a plant and provide structure. Roots do this AND are the interface to water and nutrients. Alga do not have roots because alga grow in water. There was no need to evolve roots because alga can interface throughout the organism with water. Side note: Mosses and liverworts are unique because they are terrestial but also have rhizoids. These usually grow in wet areas because they do not have the specialized tissues of plants such as roots and a vascular system. They still have the algae legacy of interfacing with water through primitive leaves. Double sidenote: This is why I find seagrasses so interesting. Plants evolved from algae to take advantage of niches on land, specialized tissues, etc etc. And then, possibly on 4 seperate occasions, evolved further to back to the water adapting their more complex tissues ot deal with water-rich environs.

farfromsea
08/25/2016, 01:55 PM
Sweet thanks love reading about this stuff.