Alocasia macrorrhizos and A. cucullata

From: LariAnn <AROIDIAN at worldnet.att.net> on 2009.09.04 at 23:35:08(19936) Peter and fellow aroiders, I need to jump in here and share what I've observed in my hybridization work with all of the species mentioned in recent posts (A. macrorrhizos, A. odora, and A. cucullata). Now, in my experience there are quite a few A. macrorrhizos cultivars available, and one I know of seems to be, as Peter mentiond, a culton of A. odora. However, most of the ones I call "A. macrorrhizos" have significant differences in floral morphology and in addition, are nearly genetically incompatible with what I have come to call the A. odora group. This group includes A. odora, A. gageana, A. odora 'Azurea', A. odora 'Indian' and A. cucullata. In hybridizing with both groups, I have found, first, that a cross of A. macrorrhizos and A. odora yields sterile offspring. A cross between A. odora and A. cucullata yields fertile offspring. Likewise, a cross between A. odora and either A. odora 'Azurea', or A. odora 'Indian' yields fertile offspring. Crosses between cultivars or varieties of A. macrorrhizos (such as blackstem, lutea, Borneo Giant, portei) yield fertile offspring. It is my position that genetic work can indicate the specific nature of various plants. Thoughts? LariAnn +More Aroidia Research _______________________________________________ Aroid-L mailing list Aroid-L@www.gizmoworks.com http://www.gizmoworks.com/mailman/listinfo/aroid-l

From: Peter Boyce <phymatarum at googlemail.com> on 2009.09.06 at 06:56:11(19945) Hi LariAnn, To re-iterate my reply to Tony, Certainly 'species' such as A. macrorrizos and A. cucullata bend the boundaries a lot. What is of course interesting is that A. macrorrhizos (notwithstanding its doubtful 'pure' species status) is definitely related (and here we are talking molecularly) to some unquestionably 'good' species, such as A. portei and A. flabellifer, which poses even more difficulties. It is also problematic to talk about utilization of cultivars, especially those that are selections of what may themselves be cultivars, albeit so long-standing that they have effectively stabilized and function as species, even to the extent that they have lost the ability to hybridize with other elements of what was once a single gene pool. The bottom line is that, at present, we can only be sure that A. macrorrhizos and A. cucculata are NEVER found away from human disturbance in 'habitat' and furthermore, away from the attentions of horticulturists are remarkable morphologically stable. As a final thought on this, it is also important to remember that species framework, and the interspecific crossing is often in nature not just a matter of 'incompatibility'. Distribution, flowering time even down to the level of time of day, and how these barriers function to manage pollinators, or select for a particular pollinator guild, are as much, if not more, a barrier than simple unrelatedness. If ever an example was needed of the role of pollinator guild niche selection, the orchids of the Stanhopineae contain numerous examples. Very best Peter +More -----Original Message----- From: aroid-l-bounces@gizmoworks.com [mailto:aroid-l-bounces@gizmoworks.com] On Behalf Of LariAnn Sent: 05 September 2009 07:35 To: 'Discussion of aroids' Subject: Re: [Aroid-l] Alocasia macrorrhizos and A. cucullata Peter and fellow aroiders, I need to jump in here and share what I've observed in my hybridization work with all of the species mentioned in recent posts (A. macrorrhizos, A. odora, and A. cucullata). Now, in my experience there are quite a few A. macrorrhizos cultivars available, and one I know of seems to be, as Peter mentiond, a culton of A. odora. However, most of the ones I call "A. macrorrhizos" have significant differences in floral morphology and in addition, are nearly genetically incompatible with what I have come to call the A. odora group. This group includes A. odora, A. gageana, A. odora 'Azurea', A. odora 'Indian' and A. cucullata. In hybridizing with both groups, I have found, first, that a cross of A. macrorrhizos and A. odora yields sterile offspring. A cross between A. odora and A. cucullata yields fertile offspring. Likewise, a cross between A. odora and either A. odora 'Azurea', or A. odora 'Indian' yields fertile offspring. Crosses between cultivars or varieties of A. macrorrhizos (such as blackstem, lutea, Borneo Giant, portei) yield fertile offspring. It is my position that genetic work can indicate the specific nature of various plants. Thoughts? LariAnn Aroidia Research _______________________________________________ Aroid-L mailing list Aroid-L@www.gizmoworks.com http://www.gizmoworks.com/mailman/listinfo/aroid-l _______________________________________________ Aroid-L mailing list Aroid-L@www.gizmoworks.com http://www.gizmoworks.com/mailman/listinfo/aroid-l

From: LariAnn <AROIDIAN at worldnet.att.net> on 2009.09.06 at 18:01:41(19947) Peter, Interesting thoughts - I would think that if a variety, cultivar or hybrid has stabilized to such an extent that it comes true to seed and functions as a species, as you described, then wouldn't that mean it has actually become a new species, in effect? Isn't that one way that speciation manifests itself? Whether it took 100 years or 1000 years, that should not make it any less of a new species, should it? Regarding the barriers to crossing, all of the barrier factors you mentioned, with the exception of genetic incompatibility, are factors that can be overcome by judicious hybridization work. I can preserve pollen to make up for flowering time differences, I can grow the plants together even though in habitat they may be very far away from each other, I can do my pollinations at different times of day in order to find the right time, and, of course, I can learn how to be the right pollinator myself. What I cannot do in traditional hybridization is to overcome a genetic or biochemical barrier to the production of viable pollen or ovules, or to the growth of the pollen on the stigma. However, as a result of my work, I've done some hybridizations that I actually thought were genetically impossible. The most remarkable example is my hybrid of A. odora and A. reginula. Predictably, the progeny are sterile, but the plants are beautiful. Perhaps, in time, the plant may stabilize genetically and manifest fertility. Kind regards, LariAnn +More _______________________________________________ Aroid-L mailing list Aroid-L@www.gizmoworks.com http://www.gizmoworks.com/mailman/listinfo/aroid-l

From: Peter Boyce <phymatarum at googlemail.com> on 2009.09.07 at 06:43:45(19952) LariAnn, The answer to your first para is a definite yes, and in fact there is such a category for such seemingly stable taxa where the hybridity is known or at least heavily suspected - nothospecies (literally 'bastard' species). There are a couple of Cryptocoryne (purpurea and the recently describe timahensis) that are just this. The problem with A. macrorrizos and A. cucullata is that the 'parentage', if they are of hybrid origin, is unknown and short of an extensive set of experiments with possible 'known suspects' (e.g., odora, navicularis, etc.) will probably remain so unless there is a chance 'discovery' in the wild. Very best Peter +More -----Original Message----- From: aroid-l-bounces@gizmoworks.com [mailto:aroid-l-bounces@gizmoworks.com] On Behalf Of LariAnn Sent: 07 September 2009 02:02 To: Discussion of aroids Subject: Re: [Aroid-l] Alocasia macrorrhizos and A. cucullata Peter, Interesting thoughts - I would think that if a variety, cultivar or hybrid has stabilized to such an extent that it comes true to seed and functions as a species, as you described, then wouldn't that mean it has actually become a new species, in effect? Isn't that one way that speciation manifests itself? Whether it took 100 years or 1000 years, that should not make it any less of a new species, should it? Regarding the barriers to crossing, all of the barrier factors you mentioned, with the exception of genetic incompatibility, are factors that can be overcome by judicious hybridization work. I can preserve pollen to make up for flowering time differences, I can grow the plants together even though in habitat they may be very far away from each other, I can do my pollinations at different times of day in order to find the right time, and, of course, I can learn how to be the right pollinator myself. What I cannot do in traditional hybridization is to overcome a genetic or biochemical barrier to the production of viable pollen or ovules, or to the growth of the pollen on the stigma. However, as a result of my work, I've done some hybridizations that I actually thought were genetically impossible. The most remarkable example is my hybrid of A. odora and A. reginula. Predictably, the progeny are sterile, but the plants are beautiful. Perhaps, in time, the plant may stabilize genetically and manifest fertility. Kind regards, LariAnn _______________________________________________ Aroid-L mailing list Aroid-L@www.gizmoworks.com http://www.gizmoworks.com/mailman/listinfo/aroid-l _______________________________________________ Aroid-L mailing list Aroid-L@www.gizmoworks.com http://www.gizmoworks.com/mailman/listinfo/aroid-l

From: "mossytrail" <mossytrail at hctc.com> on 2009.09.09 at 01:56:07(19977) So you are saying they appear to be cultigens? But cannot cultigens have valid species names (e.g., Zea mays)? And in that case, there can then be named cultivars of such cultigens (e.g., Zea mays 'Ruby Queen'). Jason Hernandez +More Naturalist-at-Large > Certainly 'species' such as A. macrorrizos and A. > cucullata bend the boundaries a lot. What is of course > interesting is that A. macrorrhizos (notwithstanding its > doubtful 'pure' species status) is definitely related (and > here we are talking molecularly) to some unquestionably > 'good' species, such as A. portei and A. flabellifer, > which poses even more difficulties. It is also problematic > to lalk about utilization of cultivars, especially those > that are selections of what may themselves be cultivars, > albeit so long-standing that they have effectively > stabilized and function as species, even to the extent > that they have lost the ability to hybridize with other > elements of what was once a single gene pool. > > Forgive me if I appear to be avoiding answering your > suggestion. But the fact is that I am not sure HOW to > answer. The bottom line is that, at present, we can only > be sure that A. macrorrhizos and A. cucculata are NEVER > found away from human disturbance in 'habitat' and > furthermore, away from the attention of horticulturists > are remarkable morphologically stable. > > As a final thought on this, it is also important to > remember that species framework, and the interspecific > crossing is often in nature not just a matter of > 'incompatibility'. Distribution, flowering time even down > to the level of time of day, and how these barriers > function to manage pollinators, or select for a > particular pollinator guild, are as much, if not more, a > barrier than simple unrelatedness. If ever an example was > needed of the role of pollinator guild niche selection, > the orchids of the Stanhopineae contain numerous examples. > > Cheers > > Pete > _______________________________________________ Aroid-L mailing list Aroid-L@www.gizmoworks.com http://www.gizmoworks.com/mailman/listinfo/aroid-l

From: Peter Boyce <phymatarum at googlemail.com> on 2009.09.09 at 05:31:48(19980) We don't know what they are. -----Original Message----- From: aroid-l-bounces@gizmoworks.com [mailto:aroid-l-bounces@gizmoworks.com] +More On Behalf Of mossytrail Sent: 09 September 2009 09:56 To: aroid-l@gizmoworks.com Subject: Re: [Aroid-l] Alocasia macrorrhizos and A. cucullata So you are saying they appear to be cultigens? But cannot cultigens have valid species names (e.g., Zea mays)? And in that case, there can then be named cultivars of such cultigens (e.g., Zea mays 'Ruby Queen'). Jason Hernandez Naturalist-at-Large > Certainly 'species' such as A. macrorrizos and A. > cucullata bend the boundaries a lot. What is of course > interesting is that A. macrorrhizos (notwithstanding its > doubtful 'pure' species status) is definitely related (and > here we are talking molecularly) to some unquestionably > 'good' species, such as A. portei and A. flabellifer, > which poses even more difficulties. It is also problematic > to lalk about utilization of cultivars, especially those > that are selections of what may themselves be cultivars, > albeit so long-standing that they have effectively > stabilized and function as species, even to the extent > that they have lost the ability to hybridize with other > elements of what was once a single gene pool. > > Forgive me if I appear to be avoiding answering your > suggestion. But the fact is that I am not sure HOW to > answer. The bottom line is that, at present, we can only > be sure that A. macrorrhizos and A. cucculata are NEVER > found away from human disturbance in 'habitat' and > furthermore, away from the attention of horticulturists > are remarkable morphologically stable. > > As a final thought on this, it is also important to > remember that species framework, and the interspecific > crossing is often in nature not just a matter of > 'incompatibility'. Distribution, flowering time even down > to the level of time of day, and how these barriers > function to manage pollinators, or select for a > particular pollinator guild, are as much, if not more, a > barrier than simple unrelatedness. If ever an example was > needed of the role of pollinator guild niche selection, > the orchids of the Stanhopineae contain numerous examples. > > Cheers > > Pete > _______________________________________________ Aroid-L mailing list Aroid-L@www.gizmoworks.com http://www.gizmoworks.com/mailman/listinfo/aroid-l _______________________________________________ Aroid-L mailing list Aroid-L@www.gizmoworks.com http://www.gizmoworks.com/mailman/listinfo/aroid-l

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