Are orchids C3, C4, or CAM plants?

[wwhitten]

Katia Silvera (Univ. of Nevada) is studying the phylogenetic distribution of CAM in orchids. She has found that it has evolved repeatedly in different orchid lineages, and is most common in orchids from hot, low-elevation habitats. Here's a link to one of her papers: Crassulacean Acid Metabolism and Epiphytism Linked to Adaptive Radiations in the Orchidaceae -- Silvera et al. 149 (4): 1838 -- PLANT PHYSIOLOGY

[epiphyte78]

If anybody is interested here's a write-up I recently posted on CAM Orchids.

[gnathaniel]

Great write-up, thanks for the link!

--Nat

[GardenTheater]

Thanks for the link.

[Wrebbitrocks]

i wish i knew this last year, there was a question about this on my AP Biology test

[taulmaril]

Very interesting, thank all you for links, I´m looking for info about CAM and orchids, aiming to better care orchids and of course because I´m curious about orchids and their world.

Thank you, ciao.

[Eyebabe]

I have a practical question regarding this

I am interested in HOW the Carbon mechanism relates to the care and culture of the orchid.
Do C3 plants need less light? More Nitrogen? More water?
Why would higher elevation lead to CAM? Would a CAM plant therefore need more airflow and or light? Would it be more prone to rot?

Science is that much better when it evolves into a practical application imo

[King_of_orchid_growing:)]

To put things into perspective...

Many (I hesitate to say "all") cacti and succulents are considered CAM plants.

Some Masdevallia spp. are considered C3.

I think that the types of carbon fixation is only helpful in horticulture for having a basic idea of how to care for the plant if, say, the habitat information is missing.

Based on the method of respiration and carbon fixation, you can kinda guess at the general climates of the habitat in which the plant comes from. Basically whether they originate from warm and/or semi-arid or arid areas; or whether the plant comes from cooler moderately humid to super humid habitats with moderate to heavy rainfall.

A note: Knowing the plant's method of respiration/carbon fixation does not usually nor necessarily clue anyone into the seasonality of the rains of where the plant(s) originate.

As with any living creature, respiration in plants usually results in some water loss. And that's where it starts getting more meaningful to a hobbyist or horticulturist.

I've found that this information is usually much more applicable for biologists in a lab or for environmental sciences.

This is my .

[Discus]

I imagine if you went around enriching your greenhouse with CO2 it would certainly help you understand what time of day you ought to be enriching the air in there with CO2 (assuming all your plants were the same metabolism). Of course, very few hobby growers do this, so it's somewhat academic still...!

[lusenok]

Epiphytic orchids have quite small root surface compared to other plants so they may have problems absorbing and retaining enough water. There is ought to be some way to conserve water especially if the plant doesn't have pseudobulbs. I would guess that phals and vandas are definitely CAM plants and the rest is either C3 or CAM as well.