A slowly accumulating, descriptive repository of plants growing
in the Bay of Islands by Robin Booth www.sub-tropicals.co.nz
One of the most spectacular tropical, deciduous, flowering trees that I know starts to flower in the gardens here in March, April, May. Called the Floss Silk Tree (Ceiba speciosa syn Chorissia speciosa), it comes from Brazil and Northern Argentina where it can grow into a big tree over many years. This beautiful genus was cultivated by the South American indigenous peoples long before the arrival of Europeans.
The Floss Silk Trees are hardy trees which can withstand light frosts, droughts, wind and even coastal conditions. I have been told of one growing close to the sea at Ruakaka and doing well. They do best in free-draining soils with reasonable fertility. An occasional water during the summer dry will make them grow very quickly.
The first thing one notices when standing beside the trees are the thick based, conical spines which cover the trunks and can extend onto the branches of some of the trees. Each tree has a different coverage of thorns; some trees lack thorns entirely. The other thing that stands out is the green bark, even on the main trunk, which means that the tree has enough chlorophyll to carry on growing over the winter months. Growth in this instance means adding girth to the trunk and branches and by the end of the winter one can see the stretch marks on the bark. With time these trunks develop buttress roots.
Thorns are usually very prominent.
When the leaves start growing in the spring the branches start elongating so the tree grows larger. If the tree is young another growth flush occurs in the autumn but if mature, flower buds form and then a spectacular display of large, generally pink, but sometimes red to white, flowers with cream throats appear and cover the tree for up to three months. To set off this display, Monarch Butterflies are attracted to its nectar. Maybe this tree is part of the natural nectar source for Monarch Butterflies returning from southern America to Mexico to overwinter.
The flowers are 10 to 15 cm across, in pink shades with a cream throat speckled with brown spots and can completely cover the tree for many weeks. The flowers are not self-fertile so two or more trees are needed for pollination . The sexual parts of the flower are a long way from the nectar that the bees and the bumble bees like so they don’t do a natural pollination. I thought maybe in its native habitat that bats or hummingbirds would do the trick, then I noticed some high up flowers setting pods and around the same time I saw Monarch butterflies being attracted to the nectar - a big insect able to do the pollination!! I wonder if they act as pollinators in South America on their yearly migration back to Mexico? The Floss Silk Tree with it’s nectar may be a bonus to our local Monarch population.
After pollination a 20cm pod forms over the winter months and matures in October/ November. To release the seeds the thick husk splits open and falls to the ground leaving a hard, tight, white ‘cob’ which over several days starts to fluff up until it is about five times the volume of the original. The wind now starts to gradually tease out the fluff or kapok and blow it away carrying the relatively big seeds a short distance with it. It seems that this kapok (which used to be used for pillows and particularly life jackets for boats) is not of the highest grade, the true Kapok Tree being best, but one person looking at it thought it should spin quite well. It has a beautiful crimp and sheen to the threads. More than one tree is needed for pollination and only a few pods are set by the Monarchs so there won’t be much kapok for an industry!
I have seen reference on the net that the wood is nearly as light as balsa though I have never cut any myself.
A handsome tree for a bigger space, not one for the smaller home garden. Enjoy them when you see them in flower where they have space to grow into a mature specimen.
"What is that shrubby plant with the lovely red flowers", I have been asked over the early summer time. It is Punica granatum or the Pomegranate, a bushy round-headed tree that can grow to 4 to 5 metres high. In spring to early summer it can cover itself in beautiful, crumpled, fine-petalled, crimson flowers, which when pollinated develop into cricket ball sized , leathery skinned fruit. When mature in the autumn these fruit are yellow to red skinned and inside are many seeds each surrounded by carmine-pink flesh with a sweetly acid flavour.
The fruit can be eaten out of hand but care needs to be taken that the dividing cell walls are not eaten as they tend to be bitter. Some people eat them with sugar or salt but I like them as they are. The fleshy seeds are very ornamental and can be used as decoration on deserts, cakes etc. Juices and syrups can also be made. Grenadine, a sweet, pink syrup was originally made from pomegranates but generally now other substitutes are used. The rind of unripe fruit and the flowers give a red dye.
Single fruiting flower and fruit.
Pomegranates make good tub plants as they can stand quite dry conditions; in fact dry, warm conditions are best for fruit development and flavour. In autumn the fruit requires a dry time to mature, if not the rain causes the fruit to split. The plant can be deciduous or evergreen and will stand some frost but will not set fruit in colder areas. Naturally the plant grows around the Mediterranean through to northwest India
Pliny called the pomegranate the "Apple of Carthage", Granada in Spain is thought to have been called after the fruit. Many references are given to it in different religions.
Double flowered ones are very ornamental but don’t set fruit. Bicoloured flowering plants also occur.
Pomegranates, a tough, smaller, bushy tree which always creates interest.
Visitors from Spain were pointing out trees and shrubs they were growing and trying to grow at home and particularly pointed out the Buffalo Wood as one they had great success with.
The Buffalo Wood (Burchellia bubalina), the only species, is an attractive evergreen shrub which is not seen very often in gardens in New Zealand. It comes from South Africa and belongs to the madder family (RUBIACEAE).
The shrub grows to about 2 metres high and has leathery simple leaves and heads of eight to twelve orange-scarlet, cylindrical-urn- shaped flowers about 25mm long. The fruits are many seeded berries. Flowering starts in the spring and continues over the summer months and the dense bush looks very attractive for a considerable time.
Happy in full sun or light shade this shrub can stand light frosts but does need free draining soils so if you have clay prepare a mound of topsoil and plant it above the surrounding soil level and you should not have any problems.
Monarch Butterfly Attracting Flowers.
This time of the year, when the Swan Plants have finished flowering, I have found in my garden is the time when Monarch Butterflies start grouping together for nectar sources to help get them through the winter. This year is the first year that an uncommon tree I have here has flowered profusely and it has been number one on the Monarchs list. It is called Oreopanax (possibly capitatus or confusum) and belongs to the Aralia family to which Ivy belongs. There are about 80 different species which come from Mexico down into South America which corresponds with the Monarchs natural range. This Oreopanax is an evergreen tree growing to about seven metres though it can be kept pruned to a lot smaller. Leaves are quite big, firm and a lovely shiny green, sometimes simple and sometimes palmate. I have found that they are grown in glasshouses in Europe for the cut foliage trade as they last well. The flowers are small, white and in clusters that stand above the foliage. A sight to behold when covered with Monarchs. Bees and wasps also really enjoy the nectar as does the occasional other butterfly.
The tree needs to be grown in a free drained soil with some sun though I haven’t tried it in shade which it will probably handle. It seemed to be quite happy in the dry period we have just had, will stand a light frost and seems to be alright in wind as it is quite a sturdy tree.
Another related plant, the Tetrapanax (Rice Paper Plant) will also attract Monarchs in quite big numbers but this plant comes from Taiwan. Has anyone noticed whether they are attracted to our native Pseudopanax or Neopanax?
Tithonia and Montanoa are also great attractants at this time of the year but the Oreopanax seems to be the best.
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