R is for……. Rhoiptelea chiliantha

Rhoiptelea chiliantha used to be in its own family, the Rhoipteleaceae, until the Angiosperm Phylogeny Group moved it into the Juglandaceae in their review in 2009 (APG III). This review immediately made it the oldest of the walnuts.

The only member of the monotypic genus Rhoiptelea, the ‘Horsetail’ tree is listed as vulnerable on the IUCN Redlist. Growing in Southern China and across the border into Vietnam the tree is found only singly or in small groups. However it is also a re-coloniser of cleared ground and thus the Cardamom plantations that are encroaching on its forest habitat also provide this species with an opportunity. Alas seedling mortality is high  and thus the re-population of cleared areas does not compete with the clearing itself.

Its fossil history places it securely in the latest Cretaceous and proves that the genus at least had a much wider distribution than it currently boasts. Fossilised pollen grains that are assigned to the genus Plicapollis from the Late Cretaceous are very similar to the pollen of Rhoiptelea and there are also pollen fossils that are actually assigned to Rhoiptelea from the Maastrichtian (the very latest stage of the Cretaceous) of North America. There is a macro-fossil record of fossilised fruit that has been assigned to Rhoiptelea from the Maastrichtian of Europe too but alas these seeds have few identifiable characteristics and thus their relationship to the Rhoipteleaceae needs to be reviewed.

Here in the ‘Fossil’ garden we have a plant of Rhoiptelea chiliantha which, on receiving it from a good friend, soon became a favorite tree. Little grown and very little known this species truly deserves to be more widely appreciated for its wonderful multi-pinnate leaves, with their winged petioles, that emerge the deepest red in the spring.




Q is for……… Quercus

A guest blog by Fernanda Castano, a paleontologist from Argentina. @ferwen on Twitter and blogger at paleonerdish.wordpress.com

The genus Quercus, in the family Fagaceae, is commonly referred to as oak. The group comprises more than 500 species and several hybrids and includes deciduous and evergreen species. The genus is native of the Northern Hemisphere and is therefore a genus that migrated during the Pleistocene, from the cool northern temperature zone to the tropics in the south.

Although the geological history of this genus could be traced back to the early Paleocene, the earliest reliable Quercus fossil in North America is from the Middle Eocene Oregon flora.

The leaves are spirally arranged and have various shapes, colors and textures with the margins entire, lobed, or toothed. The fruit is a nut called an acorn. The leaves and acorns of the oak posses a toxicity risk due the presence of tannic acid and may cause kidney damage and gastroenteritis. The pollen grain, Quercoidites, is tricolporate.

Oak wood was used in the construction of European timber-framed buildings and for the construction of ships until the 19th century.

In Greek mythology, the oak is the tree sacred to Zeus, while in the Norse mythology, the oak was sacred to the thunder god, Thor. Today, the oak is still a symbol of strength and endurance and has been chosen as the national tree of many countries.

Foliage and acorns of Quercus robur. From Wikipedia Commons.

Foliage and acorns of Quercus robur. From Wikipedia Commons.

Quercoidite pollen grain (Miocene) From Taylor et al, 2009.

Quercoidite pollen grain (Miocene) From Taylor et al, 2009.

Major Oak in Sherwood  Forest, Nottinghamshire. According to folklore, it was used by Robin Hood for shelter. From Wikipedia Commons

Major Oak in Sherwood Forest, Nottinghamshire. According to folklore, it was used by Robin Hood for shelter. From Wikipedia Commons


Edith L. Taylor,Thomas N. Taylor,Michael Krings, 2009, Paleobotany: The Biology and Evolution of Fossil Plants, Academic Press.

Xing et al, 2013, A new Quercus species from the upper Miocene of southwestern China and its ecological significance, Review of Palaeobotany and Palynology, Elsevier.

P is for….Proteaceae

This is a group of plants very close to my heart. You could even say that I am addicted to them.

They have a huge Southern hemisphere distribution including South America, Africa, Madagascar, Australia, Indonesia and New Zealand. They are also very highly speciated with around 1700 different species among over 80 genera.

It comes as no surprise then that they have a fossil record that dates back all the way to the middle Cretaceous.

The earliest putative fossil record is dispersed pollen from (Late Cenomanian) Gabon in West Africa and has been assigned the name Trioris africaensis. It isn’t then until the Late Cretaceous (Santonian) that we find the first unequivocal proteaceous fossils in Australia. There are many species identified from fossil pollen found in the Otway basin, south eastern Australia. Some of these fossils are comparable to extant species. Macrofossils of the Proteaceae are less common, but are found. Of particular interest are leaves assigned to the extinct Banksieaephyllum and Banksieaeformis but also of the extant genera Banksia, and others, from Cenozoic Australia.

Many believe that the extinct and extant distribution of Proteaceae tell the story of how the ancient continent of Gondwana drifted apart. They do make a perfect example of Antarctic flora and their distribution has helped form the theory of continental drift. Not everyone is agreed on this though. Recent genetic evidence shows a close link between the Western Australian and Southern African species. Some believe this makes long distance seed dispersal an alternative force in their distribution and partially brings into question the mechanism by which they spread across the Southern Hemisphere.

They are represented in the fossil garden by species from South America, Africa, Australia and New Zealand and a walk around the garden to look at the species we have forms an interesting story of planet Earth’s prehistory.

Lomatia myricoides


Banksia ericifolia


O is for…

A family of ferns who’s heritage takes us back nearly 300 million years to the very end of the Carboniferous.
Today there are only four extant genus in this family (Osmundastrum, Osmunda, Todea and Leptopteris) but the fossil record shows it was once a very much larger. Thamnopteris, Zalesskya, Chasmatopteris, Osmundacaulis, Aurealcaulis, Osmundites, Osmundopsis, Todites, Anomopteris, Osmundacidites and Paleosmunda are all fossil genera in the Osmundaceae. Certainly in the Jurasic Osmundaceae made up a large proportion of the understory in forests made up mostly of Araucaria, podocarps and taxodiaceae.
The Osmundaceae are represented in the fossil garden by Osmunda regalis, Osmunda claytoniana, O. japonica, O. banksiifolia, O. bromelifolia, Osmundastrum cinnamomium, O. cinnamomium var. asiaticum and Todea barbara.

N is for….

Neuropteris was a genus of extinct plants that had a unusual combination of characters. Hailing from the coal swamps of the Carboniferous it had the leaves and trunk of a tree fern but reproduced by means of seed! From a group of plants known as Seed ferns or pteridosperms they were actually more closely related to conifers and flowering plants than ferns. Weirdly, although the seed were often born on special branches they were also to be found along the midrib of the fronds. They also produced very large pollen grains which leads paleobotanists to believe they were pollinated by insects. Their nearest relatives were probably Cycads although nothing truly like them exists today.

M is for….

So everyone knows magnolias were around with the dinosaurs right? Well kind of…
Most of the modern 220ish species of magnoliaceae probably didn’t evolve until well after the K-T extinction event that wiped out the dinos!
The fossil record for this group of plants does lead us strongly into the late Cretaceous with most genus of early magnolias now being extinct. There are however two lines that have survived through to this day that were well represented in the fossil record of the Cretaceous.
Liriodendron (the tulip trees) are a genus consisting of 2 species L. chinense and L. tulipifera and Manglietia a genus consisting of 29 species although it was once bigger (many are now lumped together in the genus Magnolia) Their presence in the late Cretaceous is given away by a number of fossils, mostly fossil seeds and leaves.
A number of fossil genera that can be linked to the magnoliaceae take us much further back to about 110 million years in the Albian of the early Cretaceous. This is where we find fossils of Archaeanthus lunnenbergeri and Liriophyllum. Archaeanthus and Liriophyllum are found in association with each other and are thought to have been born by the same plant. Liriophyllum is similar in general morphology to Liriodendron but differing in leaf structure and the fruiting structure Archaeanthus differs from extant Magnolias.
Other Magnoliaceae fossil species of the Cretaceous are Liriodendroidea, Padragkutia and Litocarpon.
The Magnoliaceae are represented in the fossil garden by Magnolia (manglietia) chevalieri, M. Insignis, M. grandiflora, M. kobus var. stellata, M. sieboldii, Lireodendron chinense and L. tulipifera.

L is for…..

The giant scale trees of the Carboniferous (350-290 million years ago) were related to modern day Club mosses and even more closely to Quillworts. Growing to a maximum size of 30m with trunks nearly a meter in diameter they formed the canopy of what is now termed the ‘coal forests’.
They reproduced by spore and probably only lived for 10 to 15 years. Most species were probably monocarpic (reproducing once and then dying).
Growing in a warm, carbon dioxide rich (levels were 3 times that of preindustrial earth) environment was the factor that may have allowed such growth in such a short space of time.
Often dubbed giant club mosses they were eventually out competed by the gymnosperms (cycads and pines) and their kind only persisted in a much smaller form eventually becoming our modern day Quillworts.
We currently have the lake quillwort (Isoetes lacustris), Stags horn clubmoss (Lycopodium clavatum) and Northern fir clubmoss (Huperzia selago) growing in the fossil garden.

K is for……

The fossil genus Kasicarpa is known from fruit, flowers and leaves from the Chulym-Yeni-Sey depression in western Siberia.
Unusually it shows characteristics of 2 unrelated families of plants, the Platanaceae (Planes) in the Proteales and the Hamamelidaceae (Witchhazels) in the Saxifrageales.
When originally discovered scientist found the fruit easily placed in the Platanaceae and the leaves were originally described as Popullites pseudoplatanoides (a poplar that looked like a plane). This all caused a bit of confusion but has since shown a relationship between the two extant families with members of the sub family Altingioideae (liquidambar family) in the hamamelidaceae being most similar.

J is for…..

Jerseyanthus calicanthoides
Yes you can tell from the name Jerseyanthus is another member of the Calicanthaceae just like Idiospermum.
From fossils described as recently as 2004 and discovered not long before that in the Raritan formation of New Jersey in The USA, Jerseyanthus dates back to the Late Cretaceous (about 90 million years ago).
It has been placed as a sister group to the genus Calycanthus which still inhabits the USA. In fact Jerseyanthus really only has very minor differences from modern day Calycanthus and Chimonanthus (the number of tepals being the main one).
We have both Chimonanthus praecox and Calycanthus floridus as representatives of the Calycanthaceae in the fossil garden.

I is for…..

Idiospermum hales from the Daintree national park in Queensland, Australia. It was discovered in the late 19th century having previously only been known from their fossil record (making them what is known as a Lazarius taxon). Unfortunately the botanist that identified the plant from samples brought to him by loggers misidentified it as a Calycanthus (it is actually a member of the Calycanthaceae) When he visited the area where it had been found he saw it had been clear felled and thus the species was believed to have become extinct again! Then in 1971 it was rediscovered after some cattle grazing in the forest started to die. The poisonous seeds of the ‘Idiot plant’ where discovered in their gut.
Idiospermum actually means unusual fruit pertaining to the fact that its seed is a naked plant embryo. It is also unusual in that it can have between 2 and 5 cotyledons (seed leaves) making it neither a monocot nor dicot!
With fossils resembling Idiospermum (Virginianthus calycanthoides) aged at 120 million years and phylogenetic data placing it as one of the earliest extant (alive today) species of flowering plant. The evidence points to it being a true ‘fossilplant’.
I wish I could grow it here in North Wales but alas the garden just isn’t hot enough!