That is a very big question. But broadly speaking it is very common that plants in the same family and even the same species can have widely differing requirements. A few examples: Ranunculus aquatilis - watercrowfoot - grows in flowing rivers. Helleborus foetidus - grows in dry shade. Both are members of the Ranunculacae. In the Solanaceae eggplant is a frost tender semi tropical while bittersweet (Solanum dulcamara) is a bone hardy climber. The daisy family (Compositae) has members ranging from large shrubs to tiny alpines which live in habitats from saltmarshes to mountain tops. The Rosacae covers apple trees to strawberries via cherries, pear,roses and raspberries. Within species the same applies: Veronica beccabunga grows in water. Veronica spicata grows in dry grassland and rocks. So the moral of the story is to find out specifically what the plant you are thinking of growing really requires.

I've certainly experienced that different cultivated varieties (i.e. "clones") of the same species grow differently, and respond differently to certain variables.

I have "known" Bihai for years from a different forum and I trust that she knows what she is saying about those particular plants. She is a very experienced grower of tropical plants. I would never hesitate to believe her. :) I don't grow Alocasias myself.

In general, yes, some same species (you probably mean Genus or Family) plants have different requirements or likes and dislikes.

buy and flora,thnx so much for your articulate explanation! how fascinating!
best,
mindy

hey flora,
"Veronica beccabunga grows in water. Veronica spicata grows in dry grassland and rocks." refers to two DIFFERENT species, not the same species. Both plants are veronicas but Veronica is a GENUS, not a species. Spicata and beccabunga are two different species with two different cultural needs. Do you know of two examples in the same SPECIES that have different cultural needs?

cool, can you give me an example of two different cultivars(same species) w/ different needs?

I'm wondering if bihai had a word slip, because Zanthosoma is a GENUS, not a species.Maybe she meant to say that two different plants in the same GENUS can have different cultural needs (now, this concept I already understood!)??

gg, where are you?

thanks again,
mindy

I'd have to think it was a question of symantics more than anything else......a lot of folks use the term 'species' when referring to a specific genus, although they are not interchangeable. I've been guilty of that myself :-) I can readily accept that marked cultural differences within the same genus can occur but I'd think it far less likely to have similar qualifiers within the same species. Differences within species would either be at the cultivar level or with variations or forms and it would be difficult to extrapolate that these subtle distinctions would generate radically different growing requirements. In fact, I can't think of any off the top of my head that demand anything other than perhaps more or less sun/shade or that offer greater or less cold tolerance/winter hardiness.

As an example, let's take the recent thread on Iris pallida (and its grape scent). Iris pallida is closely related to hybrid bearded iris and it needs the same growing conditions. It is not a water iris, like one text alluded to, and will not grow in ponds, streamside or in boggy conditions - like the TBI's, it wants well-drained soil and sun. It doesn't make any difference on whether it is the straight species of I. pallida or 'Variegata' or 'Argentea Variegata' - none will be happy in water and all require similar growing conditions. And you can spend the rest of your life looking for a bearded iris that will grow in standing water! But Iris ensata or laevigata or pseudacorus will grow in standing water and it makes no difference on cultivars within those species - they will all grow equally well in the same conditions.

I think it was just a misuse of the word "species". But I'd be interested in what examples CPG has up his sleeve if he feels differently :-) I just cannot think of any that would fit this explanation. At the family or genus level, sure, but at the species level......?? Can't think of any examples that would apply.

Yes, the use of the terminology can be somewhat vague. When I hear of species, I think of the specific epithet, and not the genus or higher.

Any variegated or gold-leaved form will require slightly different conditions than the plain green-leaved form. For example, the gold-leaved versions of A. vulgaris would require somewhat more shady conditions, and possibly even more moisture, than the regular form.

Relatively tall vs dwarf cultivars of a species would also have different requirements for moisture and likely nutrients. For example, 'Pouffe' and 'Loddon Anna', both cultivars of Campanula lactiflora.

While somewhat different (as they are typically hybrids), consider the difference in mildew resistance between cultivars of Monarda and Phlox (Paniculata).

In commercial production, we note in particular that different varieties of the same species may respond differently to plant growth regulators.

"Differences within species would either be at the cultivar level or with variations or forms and it would be difficult to extrapolate that these subtle distinctions would generate RADICALLY DIFFERENT growing requirements."
YAAAAAY gg!!! That is exactly the answer that understood the question I was asking. We are so LUCKY to have you on GW. whew!! Hopefully after this, more of us will understand the :
Family
Genus
Species
Cultivar
format for botanical nomenclature. The way I have now memorized it is: F,G,S-- all progressive in the alphabet, with C tacked on at the end! It might be able to stick in my dense brain now!

best,
mindy
www.cottonarboretum.com/
a teaching website

"Ad hoc, ad loc, quid pro quo. So little time and so much to know!"- Yellow Submarine

arbo return - my bad. Family: Scrophulariaceae Genus: Veronica Species: beccabunga etc.

However, your original question asked about 'WITHIN THE SAME FAMILY OR SPECIES'. I took this to mean within the same family or within the same species ie 2 separate concepts. Hence the examples from within families. The examples where I mixed up genus and species were a daft mistake. As coolplants guy says within species cultivars can have different requirements. For example they can have different tolerance of cold temperatures. eg Rosmarinus officinalis 'Arp' is supposed to be hardier than other cultivars.

o.k.flora, now you have me REALLY confused!
(Warning- Off Topic** on my own thread!) You appear to live in SW england but then you go and say "My bad".Did you just blow your cover? So you are American?!!or you just lived here for a few years?
where?
best,
mindy

No - no cover to blow. Just the inexorable spread of American English ;) Youngsters are actually changing the grammar of the language over here, not just vocabulary. I say 'could I have a cup of tea?', my son says 'can I get a beer?' I wouldn't say 'my bad' out loud because it would sound silly from someone my age but kids say it all the time. Also I translate a bit for the purposes of these forums. Aubergines, courgettes, secateurs, broad beans - it can get confusing for some readers.

Here is the line in Britspeak:

"arbo retum. My mistake."

And, come to think of it, this isn't really off thread is it? After all we are all the same species, just different cultivars.

It may just be my perspective but growing/cultural requirements to me mean something very different than attributes specific selections within the same species may offer. That's where you get down to cultivar level and make assessments on which cultivar/selection may work best for you. For example, 'Arp' may be one of the hardiest forms of rosemary but it still has the same basic cultural requirements as any other cultivar -- a need for full sun, well-draining, lean soil and minimal water (once established) and fertilizing.

But maybe rosemary is not the best example as it is pretty much a single species genus (there is a another species but extremely uncommon in gardens or in distribution). Let's look at euphorbias, a genus with literally hundreds of species. Each species of euphorbia can (and most do) have very different growing requirements from other euphorb species, but within the same species the growing/cultural requirements will be virtually identical. Some cultivars may grow larger than others, some may produce larger/smaller flower heads or of slightly different coloring, some might even offer increased cold tolerance but the growing conditions - soils, water, light, nutrient demand, etc. will be the same.

And that's where I disagree with the statement mindy (or her source) posed initially: "LIKE ALL PLANTS WITHIN THE SAME FAMILY OR SPECIES, Xanthosomas are all individuals and some can be used as bog plants, where others will simply decline and rot." To be more accurate, I'd change that statement to read: "like many plants within the same family or even genus, each species of Xanthosomas is unique: some can be used as bog plants while others will simply decline and rot under similar conditions."

To be perfectly honest, if I were to read that statement without any preamble or mindy's intro to it, I would tend to interpret it exactly the same way as I wrote it -- unless you are a professional horticulturist or botanist, I doubt you make the distinctions between the various levels of plant morphology and understand what the writer was trying to say. Us geeky types tend to get hung up on the semantics but I understand the point the writer was attempting to get across regardless of the exact terminology :-)

Actually, I think flora summed up the entire discussion very nicely: After all we are all the same species, just different cultivars. If you think about it, each individual offers something unique but we all share the same basic needs.

I will respectfully disagree with the following:

Some cultivars may grow larger than others, some may produce larger/smaller flower heads or of slightly different coloring, some might even offer increased cold tolerance but the growing conditions - soils, water, light, nutrient demand, etc. will be the same.

Any (i.e. in most cases) cultivar that is 2-3 times the size of another is going to have by necessity different water and nutrient needs.

But otherwise, yes, we are mostly talking semantics. ;)

CPG, I think those distinctions are very slight........enough so that they are insignificant in the overall care of the plant. To use my euphorbia example, E. characias var. wulfenii grows easily to 6' in my climate....my neighbor's plant is peeking over the top of her 6' high fence :-) Euphorbia characias 'Humpty Dumpty' only grows to about 2-3' high. Both have exactly the same cultural requirements with regard to soil conditions, light, water and even nutrients. One just grows to be twice the size of the other. Does one consume more water or nutrients due to greater size? Possibly/probably but those needs are met just as successfully by offering the same growing conditions. One doesn't need to supply additional water or fertilizer to the larger growing wulfenii. Same thing with Japanese maples - sizes, shapes and habits/forms vary widely with the 100's of different cultivars but basic growing conditions for all remain the same - a preference for at least partial shade, well-drained, acidic soils and even soil moisture.

One doesn't need to supply additional water or fertilizer...

I would agree, but my expectation/experience, especially in garden situations, is that we typically don't provide exactly what the plant requires. ;) I would suggest that this is not necessarily a bad thing, and that in most cases, would typically go unnoticed.

Giving a large cultivar less water and/or nutrients will simply only produce a somewhat smaller plant. In some cases however, it may stress it to the point of making it slightly more susceptible to disease/insect pressures.

I believe however, that in most cases, but previous point remains valid.

Here's to dirt under your nails. ;)

gg, you are a most patient teacher; i applaud you for that.
our family dictionary did not have the word "patience" in it!

flora, "gotta" make another cultural reference>> you referred to the plant,Veronica beccabunga. I'm guessing that this is not a tongue in cheek plant name but I have to tell you that when i was growing up, a common kid's expression (yelled as you were jumping off a tree with a rope swing or something)was "Cowabunga"!!! so when i read of that veronica, all I can think is that some botanist with a sense of humor like noted nursery owners, Dan Hinkley or Tony Avent, created that species name in honor of a little girl named Becca(Rebecca)!!!
best,
mindy

here's what i found on the dg botanary site.

beccabunga Apparently derived from the German Bachbunge (brook+bunch) Another possible derivation is from the Flemish beckpunge (mouth smart), referring to the pungent leaves bek-uh-BUNG-uh

best,
mindy

flora, since you asked(!) i googled some more and found out that cowabunga was originated on the Howdy Doody Show
( a '50's kids' show that i was not allowed to watch, but loved! "too crass" for my mom !)
best,
mindy