Re: [Aroid-l] Alocasia macrorrhizos and A. cucullata

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

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