Sorry the late answer.
The problem with L. purpurata is that many varieties have been intercrossed generating a rainbow of intermediate colorations between varieties. These intermediate can't be clearly classified as one or another variety because they inherited characteristics of both parents used. For example, crossing var. striata with var. flammea has generated many intermediate flowers that have stripes and also deeper coloration in between the stripes. Crossing caerulea with roxo-violeta has generated many intermediate hues between the two. As a predictable consequence, many breeders/collectors, avid to particularize their plants, began giving different names for these intermediate flowers (like var. flamescens, aço, ardosia, vinho and so many other names). Today, chaos would be good to define L. purpurata and its varieties.
I am a simplifier. So, I am always trying to reduce things to the core and don’t agree with designations like aço, ardosia, flamescens, rosada, batata-roxa, vinho and so many other regional names. So, my answer here is guided by these principles.
Laelia purpurata is a problematic species since its first description and if the type is not well understood, then many other varieties won’t be.
Lindley characterized the type Laelia purpurata as being a flower with white sepals and petals allied to a purple lip. This is undisputable and beyond any doubt as can be seen in Paxton's Flower Garden - 1853, plate 96
SOF » Sophronitis purpurata . In other words, Lindley described as type what is normally known as semi-alba in this Alliance. And this would bring tons of problems in the future.
One of these problems is: how to call the flower that in other circumstances would be the type (petals and sepals pink/lavender, purple lip)?
Regel picked up a solution in 1872 describing the pink/lavender flower with purple lip as variety rosea (Lindenia, plate 302)
SOF » Sophronitis purpurata .
For me, this plate leaves no doubt that Regel wasn’t describing any particular color variety, but the flower that would be the type if it were not for Lindley’s description. So, the name rosea for those flowers has precedence over var. rosada, a recent proposition for the same flowers.
In short, because of Lindley’s awkward description of the type, var. rosea in L. purpurata is what normally would be the type flower.
Now, a few varieties in this line can be defined:
Striata:
purple lip, well-defined striations on the surface of the petals, white or light pink between the stripes. The stripes are clearly on the petals surface.
Venosa:
flowers like var. rosea (light pink/lavender, purple lip), but with clearly visible purple nervures/lines inside the petal tissue, not on the surface. This variety cannot be distinguished from striata by photos. You have to have the flower in person to see the difference.
(The photo is down the post, couldn't place it here for some reason)
Flammea:
petals partially covered with deep purple color, but always having a whitish, sometimes very light pink area at the base giving the impression of flames on the petals. Sepals are whitish, pink or light lavender and may have some striation too. The lip may have white areas at the midlobe, or not.
Notice the whitish sepals.
Some flowers are not easy to name between flammea and rubra because the white area at the petals base of some flammeas is very short and the sepals present some deeper striation, like the first flower above
Rubra:
the entire flower is deep purple, including the sepals. Sometimes the base of the sepals is lavender. The lip has no white on the frontal lobe and it is also common (but it is not mandatory) that it has the side lobes of deep purple inside and outside.
Sanguinea: the entire flower is of a very dark, velvety purplish red (hence the name bloody). The flower really has a velvety appearance. It is not easy to distinguish from rubra by photos, because most of times cameras do not capture the true reddish color and the velvety appearance. The link show one of the most famous, L.p. var. sanguinea 'Mentzii'
http://www.gnomosorchids.com/Laelia_...inea_Mentz.jpg
And then there are the things in between these. My approach in these cases is to simplify. I try to classify according to the most relevant characteristic the flower has. Here’s an example of an intermediate flower between flammea and striata that I prefer to classify as striata, but flammea would also be possible.
Var. caerulea:
caerulea is again a troublesome variety. The very first caerulea found was the clone ‘Werkhauseri’. Even though it is common to employ ‘werkhauseri’ as a variety, to me the correct name to designate those slate flowers is variety caerulea, not var. werkhauseri. Another name also used for the same variety is ‘ardósia’ (slate), which I find also inappropriate.
Here’s a photo showing var. caerulea extremes of coloration, bluish grey in one point and grayish blue in the opposite point. The two flowers in the photo below show this. More color on the second and it becomes roxo-violeta.
Variety roxo-violeta:
roxo-violeta is a very characteristic coloration different from caerulea as can be seen in the comparative photo. This variety is also regionally known as ‘aço’ (steel) because some flowers reminds the characteristic violet of some steel sheets. The second photo shows the two caeruleas compared to the roxo-violeta.
People also have been treating var. shusteriana as a separate variety just because of the huge lip that flower has, but this is not enough to characterize a new variety. To me, var. shusteriana is nothing more than a particular case of roxo-violeta.
Var. roxo-bispo: far different from roxo-violeta, this color variety closely reminds the catholic bishop festive clothing, hence the varietal name. The second photo shows roxo-violeta and roxo-bispo together.
That’s it; I hope this is of some help.