Inflorescence cormlets in Watsonia meriana

All corms and cormlets produced by a Watsonia are axillary. Sympodial branching is a diagnostic character of the genus, with the main corm being exhausted by producing an annual flowering stem and one or several new lateral underground corms each subtended by a basal leaf. Additional smaller corms, variously called cormlets, cormils or bulbils are typically produced in the axils of lower cauline leaves in many species including W. aletroides (Burm.f.)Ker Gawl., W. humilis Miller and W. meriana (L.)Miller.

The Watsonia inflorescence is a spike with each solitary, sessile flower subtended by an outer bract and a less robust inner bract. The weedy variety W. meriana var. bulbillifera (J.Mathews & L.Bolus)D.A.Cooke is distinguished by having the lower flowers in its inflorescence replaced by clusters of cormlets. This variety is usually a sterile triploid depending on above-ground cormlets for dispersal, and is known as bulbil watsonia.

However, some genotypes of diploid W. meriana var. meriana can produce small solitary cormlets or cormlet clusters in the inflorescence, at least in cultivation. The extent of cormlet development is variable from one year to another; they are sometimes absent and are never as large or numerous as in var. bulbillifera.

Accession 183. At the right of the picture is a typical solitary cormlet 3mm wide produced in the axil of the reduced leaf subtending an inflorescence branch – but on the outside of that branch. This has been observed on all branches in six out of eight years. To the left is a cluster of six cormlets replacing the lowermost flower on the main axis; this has only been observed once.

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Accession 187. A cluster of three cormlets replacing the lowermost flower of the inflorescence. This has only been observed once in eight years.

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I used to wonder if the cormlet clusters of var. bulbillifera might be homologous to the twelve organs (six tepals, three stamens, three carpels) in a flower. This hypothesis was attractive because, although the number of cormlets in each closely packed cluster is variable, twelve is a typical number. The observations reported here make the hypothesis much less likely. There is a gradient transition from stem cormlets through inflorescence cormlets to clusters. The position of the cormlets in accession 183, axillary to the phyllome subtending an inflorescence branch but abaxial to that branch as if an extra axillary growing point, is rather surprising.

The consistent development of inflorescence cormlet clusters is still the morphological character separating var. bulbillifera from var. meriana. However, the difference should be understood as one of degree rather than a clear dichotomy.

Accession 183 was a gift from Mr Graeme Dallimore who collected it on Mornington Peninsula, Victoria. Accession 187 is said to be Cronin material discarded from Melbourne Botanic Garden in 1995. Both readily produce seed, implying that they are diploids.

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References

Conran, J.G., Wilson, P.A. & Houben, A. (2004). Pollination and ploidy changes in South Australian populations of bulbil watsonia, Watsonia meriana (L.)Miller var. bulbillifera (J.Mathews & L.Bolus)D.A.Cooke (Iridaceae). Herbertia 57: 57-70.

Cooke, D.A. (1998) Bulbil watsonia is a variety of Watsonia meriana (L.)Miller (Iridaceae). J. Adelaide Bot. Gard. 18: 5-7.

Goldblatt, P. & Manning, J.C. (2020) Iridaceae of southern Africa. Strelitzia 42. (South African National Biodiversity Institute: Pretoria).

Watsonia fulgens

Watsonia fulgens (Andrews)Pers. based on Antholyza fulgens Andrews was regarded as a nomen confusum by Goldblatt (1989) because the type illustration could not be matched to any wild population. Andrews’ description of this plant whch had been introduced to England in 1792 was little more than a diagnosis differentiating it from Antholyza ringens (= Babiana ringens): it had much longer glabrous leaves that remained green until new growth appeared, and bright scarlet, curved trumpet shaped flowers with large spreading lobes.

Ker Gawler (1802) treated it as a distinctive variety of Watsonia iridifolia (Jacq.)Ker Gawl., which is another name of uncertain application. An illustration by Planchon (1856) under W. iridifolia var. fulgens matches a clone that is still widely grown in Melbourne although apparently not commercially available. Planchon noted that it flowered in autumn with a scape to 1-2 metres long, far exceeding the leaves, simple or sometimes branched in vigorous specimens. Plants of this name were being sold in England by 1820 (Loddiges, 1820). In New South Wales, Macarthur (1843) had a plant he called Watsonia iridiflora fulgens and presented material to the Sydney Botanic Gardens in 1831.

The following description is based on accession 180 in my collection:

Evergreen, proliferating, to 150 cm tall. Basal leaves about 4, to 60 cm long, 35 mm wide, bright green with faint glaucous striations and thin green margins. Stem leaves 2, bract-like, slightly inflated. Flowers 24-28 (to 4 open at once) on a brown axis plus 0-2 short branches. Bract acute, to 19 mm long, exceeding the internode, brown-herbaceous. Bracteole subequal, obtuse or notched at apex. Perianth intense orange-red, with a paler star inside throat, alternating red and pale stripes inside tube. Tube to 49 mm long; basal part to 23 mm long; distal part cylindric, curved, to 26 mm long, 8 mm wide at mouth. Ridges absent. Lobes semi-flared with flat margins; outer acute, oblanceolate, to 27 mm long, 11 mm wide; inner elliptic, obtuse, to 28 mm long, 14 mm wide. Stamens closely arcuate with style, anthers 11 mm long, purple with purple pollen. Style branches far exceeding anthers, red with paler stigmas. Capsule cylindric, truncate, to 25 mm long, brown. Seeds with two short wings, 8-10 mm long, dark brown.

Unlike Watsonia tabularis and W. fourcadei, this plant is undamaged by full summer sun in Adelaide as long as it gets enough water. New shoots appear in January while the previous year’s leaves are still green. Flowering is irregular any time from April to September.

There is a superficial resemblance to photos of wild W. zeyheri in colouring: orange-red flowers on a dark axis. But accession 180 is clearly separated from this species by its size, truncate capsules, autumn-spring flowering season, non-thickened leaf margins and the rather characteristic pale star marking in the flowers.

One possible origin could be a garden selection from random hybrids between W. tabularis and W. zeyheri or W. angusta, with strong, hardy growth in cultivation due to F1 vigour. An irregular flowering season is common in Watsonia hybrids between parents with differing phenologies. It also resembles my hybrids of typical W. tabularis pollinated by W. fourcadei in such features as size, flower colour and capsule shape. The four species mentioned in this paragraph are closely related and were treated as the Subsection Angustae in Goldblatt’s revision.

Below is Planchon’s illustration. The prominent leaf venation may be the artist’s interpretation of the striated glaucous bloom emphasising the longitudinal veins.

And the type illustration from Andrews. Assuming it is the same plant as Planchon illustrated, this is less informative. Perhaps it was grown in shaded or otherwise unfavourable conditions, as he described it as only 3 feet tall.

The plant known as Watsonia fulgens has been a “thing” for over 200 years. If it does not match any wild population, perhaps it should be treated as a cultivar. Unfortunately the name has been loosely applied in horticultural literature, for example to W. angusta by Campbell (1986). Watsonia fulgens sensu Montague (1930) was probably a hybrid cultivar; it was described as having pale-rose flowers appearing early in spring. It was distributed by Law Somner (1933) and may have been identical to the Watsonia fulgens described as a deep pink in Brunning’s 1905 and 1918 catalogues.

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References

Andrews, H.C. (1801) Botanist’s Repository 3: t.192.

Brunning, F.H. (1905) Manual of Seeds, Bulbs, Horticultural Sundries. (F.H. Brunning Pty Ltd: Melbourne).

Brunning, F.H. (1918) Winter Flowers, Bulbs, Spring Flowering Sweet Peas. (F.H. Brunning Pty Ltd: Melbourne).

Campbell, E. (1989) Watsonia. In Walters et al. (eds) The European Garden Flora 1: 385-386. (Cambridge University Press: Cambridge).

Goldblatt, P. (1989) The genus Watsonia. (National Botanic Gardens: Kirstenbosch).

Ker Gawler, J.B. (1802) The Botanical Magazine 17: t.600.

Law Somner Pty Ltd (1933) Law Somner Catalogue 1933-34. (Law Somner Pty Ltd: Melbourne).

Loddiges, C.L., Loddiges, G. & Loddiges W. (1820) Catalogue of Plants which are sold by Conrad Loddiges and Sons, nurserymen, at Hackney, near London. (Loddiges: London).

Macarthur, W. (1843) Catalogue of Plants Cultivated at Camden.

Montague, P. (1930) The new watsonias should be freely grown. The Australian Garden Lover 6: 33.

Persoon, C.H. (1805) Synopsis Plantarum 1: 42.

Planchon, J.E. (1856) Flore des Serres et des Jardins de l’Europe. 11: 1.

A partial checklist of named Watsonia cultivars

Watsonia is a genus of the Iridaceae with about 53 species in southern Africa. They are perennial herbs growing from corms and producing spikes of showy flowers adapted to pollination by birds or insects. The species are generally interfertile, all being outbreeders with the same diploid chromosome number. Their wide range in size, phenology and flower colour, along with the ease of working with their large simple flowers, make them attractive subjects for collectors and amateur hybridists.

During the early 20th century there was interest in commercial production of named cultivars for home gardens and cut flowers, but the genus has been rather neglected since then. The following checklist is a ‘first pass’ through the referenced publications, with a bias toward those cultivars that have been released in Australia. It is not certain if every cultivar on this list is still extant.

You can download the list as a 210Kb pdf file from this link.

Watsonia ‘Leng’

DOI: 10.13140/RG.2.2.16217.39520