Isochilus species

Week 33 Plant 2: Nov 10, 2020

Isochilus species

Week 33 Plant 2 Isochilus species Video.MOV

I would like to present second plant for this week:

Isochilus species (probably Isochilus linearis?).

This training exercise will be little different from just judging the plant.

Exhibitor was not sure if name of this plant is Isochilus linearis.

I would like to ask judges and students to make research first to identify this Isochilus and then judge as we are usually doing every week.

I did my research prior submitting this plant.

Genus Isochilus was described by Robert Brown in 1813.

Species from Mexico, Central and South America.

WCSP Kew accepted 13 species from genus Isochilus.

In OrchidPro I can find 32 awards - Isochilus carnosiflorus and Isochilus linearis the most common (Isochilus major, Isochilus chiriquensis, Isochilus unilateralis, Isochilus amparoanus and Isochilus aurantiacus also presents there).

I found that many of the Isochilus species looks very similar.

I would like to highlight leaves shape when compared Isochilus species. Our candidate has broad leaves compared to narrow leaves from some other Isochilus species.

When checking awards in OrchidPro I can see that Isochilus with broad leaves and narrow leaves awarded as Isochilus carnosiflorus and Isochilus linearis depends on time and Judging Center, and that make confusion 🤷‍♂️.

Except multiple images and video I will submit photos of the leaves and flowers which could be helpful for identification. The last image will present broad leaves from current candidate (left) compared to narrow leaves from Isochilus carnosiflorus (right).

Please read information from exhibitor:

    • 93 inflorescences;

    • Approximately 830 flowers and some buds total (9 flowers/buds per inflorescence);

    • Length of growth 32-42 cm;

    • Number of leaves. Long growths 37-44 leaves: less on short growths around 22;

    • Compare to Isochilus carnostiflorus: Isochilus carnostiflorus has more flowers per inflorescence, around 18, but not all open at the same time. Older flowers die before flowers at tip open;

    • Plant 42 cm tall and 55 cm wide;

    • Leaves - 4.3 cm x 0.9 cm.

Plant bought from Andy Orchids but Andy received original plant from Orchid Zone (California) many years ago

Judges' Comments

Al Messina

I make no pretense at taxonomy nor should any non-taxonomic qualified judge presume to identify this plant. My sole qualification is as an accredited orchid judge, and as such I will render my opinion, as flawed as it might be. I will assume the candidate is as presented, Isochilus linearis:

At approximately 830 flowers and some buds on 93 inflorescences on a nicely grown plant,it should qualify for a culture award. The question is point score. There appears to be a quite large flower-bare area presumably in the “rear” of the plant which would lower the score to the lower range, perhaps marginal.

Since the plant will have been adjudicated, any judge could request SITF confirmation and thereby we will have determined the correct species.


Thanks for allowing me to participate.

Tom Mirenda

Hi Sergey!

Both Franco and Adam believe this is Isochilus carnosiflorus! I would agree....


Adam Karremans

Director (Lankester Botanical Garden, Costa Rica)

Hi Tom, I don't know what Franco and Mario think, but perhaps it is Isochilus carnosiflorus. Of course, it is difficult to say with certainty without seeing the details. Attached is a plate.


Franco Pupulin

(Lankester Botanical Garden, Costa Rica)

Ho Tom! I hope that you and your beloved ones are fine in these surreal times.

I agree with Adam’s interpretation. The relatively broad leaves and the apical foliaceous bracts not tinged with purple point towards I. carnosiflirus or I. chiriquensis, but the inflorescence of the latter is secund, not distichous like in your sample.

Stay safe,


Rudolf Jenny

(Swiss Orchid Foundation, Basel, Switzerland)

Isochilus is not my special area and I want to be very careful to name plants of this genus. Concerning old plates you will find some of them under this link:

For me it looks very much like Isochilus linrearis, but as I said previously I don’t feel competent for this genus.

All the best


Tom Mirenda

I love the genus Isochilus very much and believe they are delightful and easy plants to grow, and should be in every collection

This particular species is a favorite based on the eye-catching dark magenta contrasting spots near the flower's center.

As well grown as this is, it is really just representative of this fine species, and not particularly exceptional at this time. Flower color on Isochilus can be very vibrant and almost fluorescent....this helps attract the avian pollinators in a dark forest environment. I have seen clones that are exceptional in this regard....this one is pretty normal. Also, the plants can grow into excellent large and densely flowered specimens. Sometimes with smaller flowered orchids, such smaller plants can have a superior presentation than a large plant....where flower power might be lost due the sheer size of the plant. Even so, I feel this species is capable of an even more thrilling show and can easily be double this size by next year if grown well. If the plant was really pristine I could see possibly granting a low CCM....but I think it is disqualified by the condition of bloom....most spikes have faded flowers and are past their peak. This is tough because there are also still buds on the inflorescences…which means that timing is difficult to get an optimal show. Even so, I really appreciate the organizers selecting plants like this, which are very worthy, but we see too infrequently on the judging table!

Carrie Buchman

Isochilus carnosiflorus

There are several awards to this species in OrchidPro including a CBR, AMs, CCM and CCE. The natural spread and color are consistent with previous awards. 9 flower & buds/inflorescence is also consistent with previous awards. The CMM (84), awarded in 2014, had 230 flowers and the candidate has 830, albeit on a larger plant. The previously award CCE (91) has 950 flowers on a plant slightly larger than the candidate. The candidate is more densely flowered on one side, and there are yellow leaves. I wish the plant were better groomed. I would nominate it for a cultural award and if it were properly groomed would score it in the mid to high 80s.

Deb Boersma

Isochilus carnosiflorus

This looks like beautifully grown plant and very healthy. Kudos to the grower.

Flower quality award

As a student, this was a tough one for me. I wish we had a picture of the flower face on like the award photos in Orchid Pro. I found it difficult to comment on the flower form without a better picture. I like the colour, but it doesn’t appear to be as intense as two that received AMs. The size of the flower was a little smaller than other awarded however, the Summer Solstice reported a NS of 0.1 cm and I wasn’t sure if this was correct. With 830 flowers it certainly is more floriferous than the ‘ACO’ with 328 flowers and slightly lower that ‘Summer Solstice’ with 950. I feel that I would not nominate this plant for a flower quality award.

Cultural Award

This plant has 830 flowers on 93 inflorescences compared to 216 flowers and 24 inflorescences for ‘Yucatan’ with a CCM and 950 flowers and 17 inflorescences for ‘Summer Solstice’ with a CCE. It is well grown, looks very healthy and is in the same size range as ‘Yucatan’. The video was taken under windy conditions so it was hard to see if the flowers were evenly distributed around the whole plant, the still pics also looked like they were taken in the wind regardless it does look like there are flowers distributed over the whole plant. I would nominate this plant for a cultural award and would give it a low CCM 82.

Bob Winkley

Isochilus carnostiflorus

Thank you for bringing this beautifully grown plant to our attention and for sorting out its identity.

Based on the award record, this is definitely a specimen plant, with very clean, bright green foliage and a very good number of flowers and inflorescences. The organization of the growths is not quite even or, in the words of the late great Phil Jesup, it's a bit higgledy-piggledy. This results in a plant with lots of inflorescences on one side and seemingly none on the other. When considering a cultural award on a plant which produces growths circumferentially I expect to see flowers all around the periphery and not just two-thirds.

I think this plant has responded well to its current culture and is doing what it should do. Since a cultural award goes to the grower, I think if the they are interested in a cultural award then some thought should be given as to how to groom the growths as they mature so that the resulting flowers are more evenly distributed around the entire plant.

As much as it pains me to say this, I would likely pass on this candidate at this time. I would thank the grower for submitting such a beautiful plant and strongly encourage them to consider more active grooming with an eye on a cultural award in the future.

All the best -

Bob W.

Deb Bodei

Isochilus (linearis?)


Researched using several authoritative websites and tools. My first species comparison had me considering carnosiflorus, but during a double check I also considered alatus and major as other possible identifications of our candidate. There is limited information available and my reference books were not current enough to include all of species in this genus. I looked at the following attributes:

plant size (42 cm tall), slight reddish-brown margins on leaves, bilobed leaves up to 4 cm in length, terete stems, a 1cm flower (approx.) and the distinct lip marking

I decided on alatus as the likely species identification of this plant. The attributes that most convinced me were the terete stems that were exposed rather than palaceous or almost completely clasping (to hide the stem) as in the case of carnosiflorus (linearis) and also the red-purple horizontal marking fully across the lip, basally as opposed to other species that only had two spots on ether side of the lip, basally. The plant and flower segment measurements seemed too small to be major. I found OrchidPro confusing and I don’t believe all the awarded plants have been identified correctly on a number of the flower and cultural awards.


I would nominate this plant for a CHM based on the different segment sizes and attributes different from prior awarded under the label name. I would include a note for SITF that I suspect it could even be alatus because of the differences. It has never been awarded under this species name and it grown well, floriferous and very attractive. It is something I would consider growing.

Thank you for including my commentary,


Sergey Skoropad

Isochilus species?!

This is very interesting entry!

Out of 13 accepted species at least 3 or 4 looks very similar - I. alatus, I. carnosiflorus, I. linearis, I. major.

I’m not a orchid scientist but will try to put some things together using OrchidPro, antiques plates and books.

As it was mentioned in initial presentation this Isochilus species characterized by broad leaves and average 9 flowers per inflorescence.

In OrchidPro I can find confusing information:

These few awarded I. carnosiflorus looks exactly like our candidate (broad leaves):

Isochilus carnosiflorus 'ACO' AM/AOS, 2018


Jorge Enrique Céspedes Trigueros

Isochilus carnosiflorus 'Yucatan' CCM/AOS, 2014


Juan Carlos

Isochilus carnosiflorus 'Castle' CBR/AOS, 1982


Unknown Photographer

All of them have broad leaves!

But some of I. carnosiflorus looks different (narrow leaves). Plus some of I. linearis looks similar to candidate.

Isochilus carnosiflorus 'Summer Solstice' CCE/AOS, 1915


Maurice Marietti

Isochilus linearis 'Francisco Adrian' CCM/AOS, 2017


Jorge Carlos

(awarded as Isochilus latibracteatus, SITF has determined this as Isochilus linearis (Sept 2018). )

When I searched antique plates on internet I found many plates with I. linearis and most of them have linearity leaves (the narrowleaf orchid).

I. major in my opinion should be larger than our candidate.

Regarding I. carnosiflorus:

In orchid book ‘Vanished Beauty - Native Costa Rican Orchids’ Vol. 1 by Franco Pupulin I found picture of I. carnosiflorus which looks very similar to our candidate (broad leaves and about 9 flowers per inflorescence).

Based on my research I believe that our candidate is Isochilus carnosiflorus!

Back to judging points:

With approximately 830 flowers on 93 inflorescences this plant could qualify for cultural award.

Unfortunately distribution of the flowers (3/4 of the plant with flowers and no flowers on the back), size of the plant compared to number of flowers can’t allow me to score high.

I would nominate this plant for cultural award and score 82-84 pts.

If this award will be in person AOS judging I would request SITF confirmation.

Thank you


José "Pepe" Portilla

(Ecuagenera, Ecuador)

Hi Sergey

Thanks for your email.

I hope this help you.

Flowers looks Isochilus alatus, and the plant looks Isochilus linearis,

Very confusing.


José "Pepe" Portilla Andrade.

Presidente Ejecutivo de Ecuagenera Cia Ltda.

Exhibitor - David and Joan Rosenfeld, NJ