the many diff. Hoya imbricata's

[frogsintn3]

Tlk abt getting a freaking headache. No wonder there is soooooo much confusion in the ant plant world. Greatly appreciate any insight. Hoya imbricata var. imbricata [green leaves & drk green speckled white/silvery leaves], Hoya imbricata var basi subcordata [drk green speckled white/silvery leaves], Hoya imbricata maxima [silver leaves],

Hoya imbricata maxima [red corona/flower--drk green speckled white/silvery leaves], Hoya  Imbricata maxima [white flower--drk green speckled white/silvery leaves], Hoya imbricata maxima [yellow corona--drk green speckled white/silvery leaves], Hoya pseudo-maxima AP1162 [drk green speckled white/silvery leaves] Mindanao, Philippines, Hoya pseudo-maxima AP1163 [green leaves] Mindanao, Philippines, Dischidia imbricata var flat  [green leaves] 

[Philpatrick]

This has some information describing the differences (not entirely in English) and includes drawings. It shows different forms. I am assuming it only describes plants found in the Philippines. Hoya maxima is not listed. Could this be because it is mainly on Sulawesi?

Year: 1919 (102 years ago).

https://www.biodiversitylibrary.org/item/1125#page/2/mode/1up

You can browser search directly in the pages or download the 600+ page file and search it that way.

There is recent information on their differences. In the past I have grown some of these but I did not explore their differences. I wish I had investigated them more, especially beyond the naked eye.

Information on Hoya maxima (Sulawesi) as a synonym of Hoya imbricata:

BLUMEA 46 (2001) 457-483

Hoya maxima herbarium:

http://www.plantsoftheworldonline.org/taxon/urn:lsid:ipni.org:names:98555-1

Also, translating the latin names suggests the basic differences.

There is much more genetic variation than is documented of course, that is life. 

[Philpatrick]

I looked again and found Hoya maxima from Celebes. There is not much information about it. It is in German. Sulawesi is also known as Celebes.

The Philippine journal of science.

https://www.biodiversitylibrary.org/item/1125#page/2/mode/1up

Page 265:

"Hoya maxima aus Nord-Ost-Celebes" (Hoya maxima from north-east-Celebes).

If I am translating it all correctly, the upper side of Hoya pseudomaxima is completely smooth without cuticular stools or fluffy hair.

Also, here is some information:

The World of Hoyas - A Pictorial Guide by Dale Kloppenburg   

http://dalekloppenburg.blogspot.com/2017/02/the-world-of-hoyas-pictoral-guide-book.html?m=1

https://issuu.com/jeanclode/docs/hoyafoliage_guida

 

 

[Derrick]

This is what IPNI (International plant name index) records for H. imbricata. https://www.ipni.org/?f=f_specific&q=genus%3AHoya%2Cspecies%3Aimbricata

Tropicos page. https://tropicos.org/name/2601517

Thus, there is probably no scientifically accepted list of possible varieties of this fairly widespread variable species. Indeed, it seems that the modern botanical trend is to mostly avoid varieties. Of course many commercial sources will try to name what they sell, often with little to no scientific or even useful to the buyer accuracy. So it is very much a case of buyer beware.

Hobbyists need commonly accepted labels for valued growth forms. That is a name that means the same to as wide an audience as possible. An ever growing (pun intended) problem in our globalist world. It is possible that widely accepted labels are used in one or more specialist Hoya groups.  I am not a Hoya specialist, so I cannot add more.

One way that new plants lacking an official name can be distributed is by adding the original collection location in "double quotes" preferably also in lower case to avoid confusion with registered cultivars. Correct grammar can surely be overlooked here. Thus as Hoya sp? "bada valley, central highlands, sulawesi".

A registered cultivar however, would be shown as Hoya imbricata 'Whatever'

 

    

 

[Philpatrick]

Perhaps determine which, of the names above, are synonymous with H. imbricata and which ones are considered seperate species? 

They are synonymous according to  BLUMEA 46 (2001) 457-483, which also states Hoya shallertiae is synonymous:

"We do not think that the variation in above-mentioned vegetative traits justifies the separation of these growth forms into separate taxa. We have therefore placed H. maxima (H. Karst.) Warb., H. pseudomaxima Koord. and H. imbricata Decne. forma basi-subcordata Koord. in synonymy with H. imbricata Decne. We suspect that H. shallertiae Burton was described from a herbarium sheet containing flowers of H. imbricata and branches of Dischidia imbricata. If so, this species would also be placed in synonymy with H. imbricata."

In some places they are listed as seperate species.

Tropicos, Kew, IPNI:

Hoya imbricata:  Tropicos, Kew, IPNI.

Hoya imbricata var. basi-subcordata: N/A

Hoya maxima: Tropicos, Kew, IPNI.

Hoya psuedomaxima: Tropicos, Kew ( considered a synonym of Hoya imbricata subsp. imbricata), IPNI.

Hoya shallertiae: Tropicos N/A, Kew, IPNI N/A.

Dale Kloppenburg has contributed a lot of information on Hoyas. Some relief here:

Kloppenburg BHL.

https://blog.biodiversitylibrary.org/2018/02/bhl-gains-works-on-diverse-plant-genus.html

https://www.biodiversitylibrary.org/search?searchTerm=Kloppenburg&stype=F#/titles

Section Peltostemma (Hoya imbricata and Hoya maxima), page 11. 

https://www.biodiversitylibrary.org/item/228164#page/17/mode/1up

Accurate data no matter how old, and direct observations help. Where do you draw the line though, or should you? Is there even a line?

There is a lot of information but how do you structure it before a migraine sets in?

To add to the confusion. The names Hoya imbricata/maxima, Hoya cf. imbricata and Hoya imbricata var. basirotunda. Have also been used. 

Also, the first picture following page 267 shows the typical form, and the flower does not look like it belongs to Hoya imbricata!

I think it boils down to asprin, acetaminophen or ibuprofen.

[Derrick]

The essential answer to the original question has already been covered under Hoya imbricata in my E book database. However, I have added a little more detail that hopefully will appear in my 2022 edition. I am soon to have heart surgery so ?????

[Philpatrick]

That is as much as I could find for the day. I hope my humor came across well for headache relief. It can be a headache. The E book database will clear up a lot of confusion. 

[Philpatrick]

It helps to have all chapters as one link. When looking up information on ant plants, referencing your book first helps a lot and saves time. I might have put some redundant or duplicate information and links above. When I searched the database the first time, not much information was on Hoya imbricata. After I posted what I found, I rechecked your database and this time information on H. imbricata was there. I am not sure why I did not see the information the first time I checked.

[Aurélien]

Hi,

It seems that's only minor variations, not recognized by modern taxonomy.

here a specimen in C.E. Sulawesi:

The best,
Aurélien