Cambridge University Botanic Garden

Buttercups at Cambridge

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The course I attended (Flowering Plant Families) is run by Cambridge University staff.  This is Dr Tim Upson introducing the course at the Botanic Garden, by the lake. We had just seen a grass snake and joked about how plants often get upstaged by animals!

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Ranunculaceae is the Buttercup family, which contains many ornamentals.  Well known members are the buttercup (obvs), Delphinium, Aquilegia and Thalictrum.  The plants are mainly herbs, with a few climbers (Clematis).  It has a world wide distribution and plants in this family contain alkaloids – some are poisonous, like Aconitum.

The family name Ranunculaceae is pronounced ran-un-queue –lacey.

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A buttercup pulled apart: this family is not characterised by the number of petals and sepals as they are variable.  Linking characters for Ranunculaceae: flower parts are free and not fused, and spirally arranged along the elongated receptacle. There are numerous stamens and carpels.

Buttercups are actinomorphic which means they are radially symmetrical, as opposed to zygomorphic (bilaterally symmetrical).  Think of a cup and saucer – the saucer is actinomorphic (symmetrical along 3 planes) but the cup is zygomorphic (symmetrical along 2 planes).

The following three illustrations of Hellebore varieties are taken from our cultivated collection. Despite names such as ‘Christmas Rose’, this plant is not in the rose family but the buttercup family.  The first is from ‘The Garden’ the monthly magazine of the Royal Horticultural Society, 1879. The second was from another horticultural magazine: Edwards’s Botanical Register by S.T. Edwards & J. Lindley, 1838, and the third illustration was taken from Paxton’s Flower Garden, 1850-53 by J. Paxton.

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A herbarium sheet of Anemone nemorosa (wood anemone), from the buttercup family, collected by Lydia Becker in Whalley Wood, April 1864 for the British Botanical Competition. Lydia Becker was a suffragette and was born in Chadderton, Manchester.Image

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Brassicaceae at Cambridge

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Last summer I spent a wonderful week in Cambridge, on the Flowering Plant Families course at the Cambridge University Botanic Garden.  It was a warm sunny week, and around 20 of us sat at microscopes in a classroom, the windows open to let in a summer breeze.  We had tea, biscuits and fresh plant material in jam jars around us.

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jars of fresh material and suggested reading

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This is the first in a series of plant identification blog posts, based on what I learnt at Cambridge.

One of the simplest plant families to start with is the cabbage family – Brassicaceae (pronounced brass ick ay see).

This is one of the simplest families to recognise as it has distinctive characteristics which are repeated.  The characters are

Sepals (calyx): 4

Petals (corolla): 4

Androecium (stamens): 6 (2 short, 4 long)

Gynoecium (carpels): 2 fused

The fruit is a siliqua – a pod like capsule with 2 united carpels.

I pulled the flower apart and laid it out so the parts are easy to see:

Rocket - Eruca sativa, Brassicaceae

This plant family is also called Cruciferae. This name comes from the cross (or crucifix) shape made by the four petals. It is easier to see in some species than others.

It is a family of annuals or perennial herbs, which contain mustard oils (glucosinolates) which give cabbage and Brussels sprouts their strong flavour.  Leaves are alternate and can be simple or toothed/lobed.

There are many economic uses – food like cabbage, rocket, broccoli and cauliflower, plus mustard and cress.  Oil is obtained from oil seed rape.  Other family members are grown as ornamental garden plants, such as honesty, stocks and wallflower.

eruca sativa

This is a herbarium sheet in the Manchester Museum of Eruca sativa (rocket). It was collected in St-Anne’s-on-the-Sea, Lancashire by Charles Bailey, one of our big collectors, in 1907. The handwritten number starting with EM, just above the printed label, is the database number we give each of our specimens.

This is a good, simple guide to the parts of a flower http://www.amnh.org/learn/biodiversity_counts/ident_help/Parts_Plants/parts_of_flower.htm