Pedigrees of the Cronin watsonias

The rediscovery of Mendel’s principles of heredity at the beginning of the 20th century inspired a surge of ornamental plant breeding by researchers, commercial nurserymen, and perhaps most importantly by individual gardeners.

John Cronin, Director of the Royal Botanic Gardens in Melbourne from 1909 to 1923, had a personal hobby of experimenting with the improvement of garden flowers. He aimed to demonstrate the application of Mendel’s laws to flower breeding, and encourage gardeners to make their own hybrids. He worked with Dahlia and other genera, but particularly the winter-growing South African watsonias, which he recognised as “everyone’s flower” – easy to grow, attractive, a natural for southern Australian gardens.

In a previous publication I lamented that the exact pedigrees of his Watsonia cultivars were lost with the destruction of his papers after his death in 1923. But now the National Library of Australia has come to the rescue with their wonderful resource of newspaper files at Trove. Cronin was a tireless populariser and communicator, speaking at the evening meetings of horticultural societies around the suburbs of Melbourne and giving interviews to journalists.

In the spring of 1904, while employed by William Guilfoyle at the Botanic Gardens, he crossed a pink Watsonia borbonica with W. borbonica ‘Arderne’s White’. This cross may be represented by the following formula (but note that the order is arbitrary, it is not known which was the pollen parent and which the ovule parent in any of the crosses discussed here):

borbonica × Arderne’s White

He noted that pink flowers were dominant over white in the F1 generation, as has been confirmed by other researchers. In spring 1907 he selected one F1 plant with tall stature, dense branching and large flowers. He crossed this with a purple Watsonia meriana and the widely grown red Watsonia aletroides, and also backcrossed it to W. borbonica ‘Arderne’s White’ to create three lines for further breeding:

1. meriana × (borbonica × Arderne’s White)

2. aletroides × (borbonica × Arderne’s White)

3. Arderne’s White × (borbonica × Arderne’s White)

Cronin’s appointment as Principal of Burnley Horticultural College in 1908 seems to have interrupted this work, and in the following year he succeeded Guilfoyle as Director of the Botanic Gardens. By 1913 he had time to resume his watsonia experiments, and on 20 March sowed seeds from his three 1907 crosses at the Botanic Gardens nursery. Six years is not an inordinately long time to store Watsonia seeds, but there would be some loss in viability which may have unintentionally favoured some genotypes over others. Cronin’s management of the plants was another possible source of selection pressure to produce watsonias adapted to Melbourne gardens: he left the corms in the ground over summer, and gave the plants no fertiliser or watering even though 1913-14 was a drought period.

This generation produced their first flowers in October 1914; Cronin stated that these resembled the 1907 selection in size and colour, and were inbred that year. I interpret this to mean that he produced an F2 generation in each of the three lines by cross-pollinating siblings, since selfing would have produced little or no seed due to incompatibility. Thus,

1. (meriana × (borbonica × Arderne’s White)) × (meriana × (borbonica × Arderne’s White))

2. (aletroides × (borbonica × Arderne’s White)) × (aletroides × (borbonica × Arderne’s White))

3. (Arderne’s White × (borbonica × Arderne’s White)) × (Arderne’s White × (borbonica × Arderne’s White))

Large numbers of these seedlings were raised in the main nursery of the Botanic Gardens. By October 1916 Cronin saw the first flowers of the inbreds, which had a wider range of colours than their parents. Some whites showed up, as would be expected from recombination, including some with flowers of improved size and form compared to the original ‘Arderne’s White’. The watsonias commercially released in the 1920s as the Commonwealth hybrids or “Watsonia Cronini” were selections from this generation.

Line 1 would have produced the many Cronin cultivars with a mixture of characters from W. meriana and W. borbonica. These often have subtle tertiary flower colours due to genes from both species influencing anthocyanin pigment production. Floral bracts are typically well-developed and obtuse, compared to the shorter acute bracts of W. borbonica. Examples include ‘Lilac Towers’, which is the most widely grown Watsonia in Australia today and may be the same as Cronin’s ‘Sydney’, and the one illustrated below which may be his ‘Maitland’.

Line 2 would have yielded flowers with long tubes and small lobes like Watsonia aletroides. The one illustrated here was discussed in a previous post.

Cultivars from line 3 are not interspecific hybrids, but selections within the species Watsonia borbonica and would include Cronin’s improved whites such as this, which may be his ‘Hobart’.

This is the same breeding program that was reported in less detail by Pescott (1926) and Cooke (1998).

It’s significant that Cronin did not use a long breeding program: the cultivars released were no more than three generations away from the original genotypes that had been imported from Africa in the 19th century. As he was working with a perennial that is normally propagated vegetatively, he could stop at the F2 with its fixed heterozygosity. I have bred watsonias four generations on from these and other old cultivars, and can attest that hybrid breakdown soon appears. Some of the resulting plants had interesting extremes of flower shape or colour, many were dwarf or weak in growth, but few were gardenable.

In the spring of 1917 Cronin presented this data to the horticultural correspondent of The Leader, and was lecturing on flower hybridisation to amateur horticultural societies with his new watsonias as exhibits. The following year he gave an interview to The Argus, repeating that his new watsonias were produced by first crossing and then inbreeding on Mendelian lines.



Anon. (1917) Melbourne Botanic Gardens – New colors in flowers – The laws of Mendel. The Leader (Melbourne), Saturday 10 November 1917 pp.13-14.
Anon. (1917) Horticultural society. The Advertiser (Footscray), Saturday 15 December 1917 p.3.
Anon. (1918) Botanic Gardens Experiments. The Argus (Melbourne), no.22,553. Monday 11 November 1918 p. 6.
Cooke, D.A. (1998) Descriptions of three cultivars in Watsonia (Iridaceae) J.Adelaide Bot. Gard. 18: 95-100.
Pescott, E.E. (1926) Bulb Growing in Australia. (Whitcombe & Tombs: Melbourne).

What is a finite self?

Take a look at whatever you call your “self”. Is it an entity with hard, permanent boundaries?

In my own experience, awareness extends across conceptual spaces that could be called fields, divided by boundaries that might be called discontinuities in awareness.

Michael Polanyi described a particular type of boundary in a series of publications in the 1960s. He introduced the theory of tacit knowledge, where information tacitly known at one level of reality is the basis of explicit understanding at a higher level. For example, whenever we read a text we are tacitly perceiving all the letters but normally notice only of the words or sentences that they spell. Many such levels may exist in a hierarchy, such as letters forming words according to rules of spelling, that form sentences according to the rules of grammar, that in turn carry meanings according to semantic rules.

Each level is a field containing a consistent set of concepts that is incomplete in that it allows its boundary to be ruled by the next higher level. The lower or proximal field contains things known tacitly but the distal field consists of things that are known explicitly, or are still unknown. The proximal field is experienced as self, the distal field as not-self or in other words the external world. For the purpose of this discussion I’ll call these Polanyi boundaries.

The old truism that anything has both an inside and an outside aspect is rediscovered from time to time. For example, the botanist Agnes Arber wrote that “The fact that each organism is both a unity intrinsic to itself, and also an integral part of the nexus which is the Whole, informs it with a basic duality.”

The subjective experience of being a self and separate from an external world – that is, the rest of the universe – was analysed by Gerbode in terms of the theory of tacit knowing. We tacitly know such things as the movement of our voluntary muscles, ideas with which we have identified, skills that have been learned and experiences internalised. All these things are within the aggregate that we think of as self. The other things that we perceive are considered to be separate from the self and therefore parts of an external world.

Another type of boundary that exists between opposing postulates in the mind was described by Stephens as occurring where postulate pairs such as “must know” and “must not be known” meet head-on like opposite flows forming a ridge, a mass that we experience as sensation. Such ridges might be called Stephens boundaries. Moreover, since one self-consciousness cannot simultaneously hold contradictory postulates, the boundary may effectively divide the mind into two fields that function as if they were independent entities.

Please note that I’m using the term postulate here to mean a causative thought, following the usage of Stephens and Gerbode, and before them of Hubbard. This isn’t quite the usual meaning of the term in English. Unfortunately, English doesn’t have any word that captures this concept exactly, and the Buddha’s Pali term saṅkhāra would be more precise. In Buddhist philosophy, saṅkhāra does not depend on self-consciousness but is actually a precondition for that consciousness.

At first sight, a Stephens boundary appears to separate a pair of entities that are both on the same level. The pair of postulates that define their boundary are not immediately recognisable as a rule imposed from a higher level that defines the boundary of the lower one.

But a Stephens boundary can also be seen as an instance of a Polanyi boundary. Both types of boundary represent an inconsistency that marks the limit of an internally consistent field. In fact, the contradictions between postulates are the source of the incompleteness or inconsistency that marks the boundary.

A pair of exactly opposed postulates forms a unity, just like the two ends of the same stick. More importantly, any Stephens boundary actually has higher and lower sides like a Polanyi boundary. The stick has a proximal and a distal end relative to the observer’s viewpoint.

The proximal field is experientially a self, which is normally a lower level field than the corresponding not-self. Self (the field of what we tacitly know) is a small portion of the whole universe (the field of what we explicitly know + what we tacitly know + everything that exists beyond our knowledge). In our everyday experience, the universe of discourse is whatever we perceive as the whole world. Any thing that we can readily view, including ourselves, is much smaller than the universe. Brotherhood with the universe can be a heady feeling when meditating under the summer stars, but taking that feeling too literally is the road to megalomania.

Any thing that we call our tacitly known “self” is an instance of what Stephens called a junior universe – an object that is selected as one side of a dichotomy, leaving the rest of the universe on the other side. Compulsive game playing compartmentalises a person into progressively smaller junior universes by successive dichotomies.

Could it be that a subjective sense of self arises from opposed postulates? If one being cannot hold both postulates simultaneously, there would be a division into self and not-self. The field of not-self can then be subdivided into various objects and even other living beings known as “them” or “you”.

Conversely, resolving the postulate opposition would resolve the perceived boundary of a self. An experimental test of this hypothesis would be to erase some contradictory postulates from one’s mind and observe what happens to the sense of self. Does it expand?



Arber, A. (1954) The Mind and the Eye: A study of the biologist’s standpoint. (Cambridge University Press).

Gerbode, F.A. (2013) Beyond Psychology: an Introduction to Metapsychology. 4th edn (Applied Metapsychology International Press: Ann Arbor).

Polanyi, M. (1968) Life’s irreducible structure. Science 160: 1308-1312.

Stephens, D.H. (1979) The Resolution of Mind: A Games Manual. (privately published: Sydney).