Articles: BULB CHAT August 2010 PDF Print E-mail
Sunday, 05 June 2011 15:59

Bulb Chat August 2010

YELLOW-FLOWERING ROMULEAS by Alan Horstmann

At the June meeting we had a variety of Romuleas in flower on the table. The flower colour was mostly yellow. Yellow is one of the most common flowers of all Romuleas. As we all know, yellow can come in many shades. The yellow Romuleas often have dark markings in the cup, but some species donít have these markings. It is soon obvious that the identification of Romulea species is near impossible using flower colour and flower markings as your only criteria.

According to Dr John Manning, recognizing the different Romulea species should firstly be based on the morphology of the corm and the tunics. Two main types of corm are distinguished. This is associated with the division of the genus into two sub-genera.

Getting back to our collection of yellow Romuleas on show at the meeting: We had Romulea tortuosa, Romulea austinii, Romulea flava and Romulea discifera on show. Romulea discifera caught us out. It was a well -grown tall specimen resembling Romulea hirta. The leaf structure and the markings in the cup were not those of Romulea hirta. Romulea discifera has a direct link to IBSA. It was first collected by Rod and Rachel Saunders.

It is found near Nieuwoudtville on the road towards Loeriesfontein. It grows in an area often visited by the thousands of visitors who go to Nieuwoudtville to see the flowers, but because it flowers earlier than most other bulbs and corms it has obviously been overlooked. As can be seen from this discussion it also resembles Romulea hirta, which is very common in that area.

Looking at the plants on show it was once again apparent that in cultivation the leaves of Romulea tortuosa are not tortuose at all. The leaves in cultivation are usually erect and twisted.

A few other Romuleas with yellow flowers to look out for would include Romulea montana, R monticola, R luteoflora, R diversiformis (common on the Komsberg), R elliptica, R malaniae, R membranacea, R saldanhensis, R citrina, R multisulcata, R viridibracteata, R sulphurea and R sphaerocarpa. There might be more but these are the ones that I can think of now. Romulea malaniae has been an enigma. It is a species that Andries de Villiers and I have gone to look for on more than one occasion. I have never seen it and I am not sure if Andries ever found it.

SPARAXIS MACULOSA

This plant was only discovered in the late twentieth century. It is still critically endangered and known to come from only two or three localities near Villiersdorp. It grows on wet clay flats in Renosterveld.

Sparaxis maculosa is closely related to Sparaxis fragrans. Sparaxis maculosa has larger flowers with dark central markings and is unscented. One to three flowers are found on a spike. The flowers are bright yellow with a dark, blackish maroon centre.

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FLORA OF MEADOWRIDGE COMMON by Fiona Watson

This area was declared a farm in 1685 by Simon van der Stel, which, in recent times, was inherited by Mrs Purcell, who with great perspicacity recorded the floral species growing on the farm. Dr Purcell collected plants which were identified by Dr Dee Snijman, They compiled a comprehensive list of 595 species, which included a significant proportion of all of the Sand Plain Fynbos species of Cape Town.

The original farm has been subject to urban encroachment, and the remaining fragment, Meadowridge Common, drew the attention in the 1990ís of Fiona Watson, who lived close by. Fiona has systematically documented all the floral species on the remaining 0.06 sq metre area, a total of 138 species including a significant number of geophytes. She found a willing ally in Dr John Manning from SANBI, who was delighted to confirm Moraea elsiae, which had not been seen for 20 years. Geophytes are not consistent in flowering every year, either in their natural cycle and the conditions during leaf formation or from an environmental insult, therefore numbers are variable.

Fiona applied her scientific training to determine whether factors such as humidity and barometric pressure provide the stimulus to flower in the Gethyllis corms.

With the cooperation of Maya Beukes, manager of the Kenilworth Race Course area, and Pat Holmes of SANBI, Fiona undertook restoration of degraded areas and filled-in wetlands. This has necessitated some creative strategies. Dumped soil was removed cunningly redeployed as a border demarcating the adjacent school football field, using a borrowed front-end loader and cooperative driver! Where species have disappeared Fiona has reintroduced them, meticulously from the same seed bank in the area. Invasive plants, including the ubiquitous opportunist grass |Eragrostis curvula, are continuously kept at bay. She has also risen to the challenges facing any open space, in particular minimising the impact of vagrants, their sleeping shelters, litter and fires. The threat of the area being commandeered for a football ground for local children was deftly side-lined, and other threats over the years. One accidental fire, although not in the optimal place, resulted in spectacular spring displays of Oxalis obtusa and Ursinia anthemoides, and the useful clearing of tufts of Eragrostis grass.

We were given a comprehensive tour of many of the flowering plants found on Meadowridge Common through Fionaís slides.

Gethyllis afra is well established, affording an opportunity to study the factors influencing the synchronicity of flowering, thus ensuring cross-pollination by bees. Fiona graphed data on atmospheric pressure and humidity in December and January, and confirmed that flowers appeared after a dip in pressure with a cold front, with or without rain.

Geophytes are well represented, and well adapted, as flowering seems unaffected by varying winter rains. Sparaxis bulbifera provides a magnificent display in spring.

Beometra uniflora grows in the damp areas, as does Geissorhiza aspera. Other species include Wurmbea, Lachenalia, Ixia dubia, Romulea, Moraea fugax, M tripetala, and Moraea elsiae, the latter being classified rare to extinct, having not been seen for 20 years and was positively identified by Dr John Manning. Fiona collected 6 seeds recently from the few plants and hopes they are successfully cultivated at Kirstenbosch. Finally the delicate Cyanella hyacinthoides, known as Ladyís fingers, flowers in spring and summer.

Terrestrial orchids found growing in the seepage areas, although do not always appear in dry years, are Corycium orobanchoides, Disa brachteata, and Holothrix villosa. Pterygodium catholicum numbers are reduced, and it seems to be disappearing, perhaps linked to the reported disappearance of the bee pollinator.

Dicots provide colour all summer, keeping the pollinators busy. Represented in varying numbers are: Lampranthus reptans, Ursinia anthemoides, Arctotheca calendula, Senecio, Heliophila africana, the pretty blue Wahlenbergia capensis and W hispidula, Monopsis debilis in the seepage area and species of Pelargonium, including P tristis, P myrrhifolium and P cucullatum, with one Geranium incanum. Aspalathus callosa and A retroflexa regrew after the small fire, as did Struthiola ciliata, Trachyandra ciliata, Oxalis obtusa and Leucodendron salignum. Erica subdivaricata flowers in January. Diastella proteoides, a Red Data species, has only 2 plants remaining, but it also occurs on Kenilworth Racecourse, (the original stock?) and can be reintroduced.

Meadowridge Common is an important link through the biodiversity corridors to other remnants of the Cape Sand Plain Fynbos, and it is fortunate for us it has been preserved through the vision, diligence and professional approach of Fiona Watson and the Friends of the Common, with assistance from Maya Beukes, Cape Nature Conservation Reserve Manager. Records have been meticulously kept and will be handed over to SANBI, and the site also used for education purposes.

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To do this month: from Rod Saunders:

Check for Amaryllis worms - they are very active at the moment.

Water your bulbs as it has been very dry. Mist seedlings

Hand -pollinate flowers to preserve the integrity of your collection.

Check the labels before your plants go dormant.  An incorrect label is easy to fix now, not easy when you only have a dormant bulb/corm!

Summer rainfall bulbs may be commencing growth. Check them and water if necessary.

Last Updated on Monday, 05 December 2011 16:03
 
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