CRITERIOS DE EVALUACIÓN Y ESTÁNDARES DE APRENDIZAJES

shortly after formation of the pollen grains, the cells in the anther wall dry up and shrink so that the pollen sacs burst open when the anther splits. The pollen grains are released and travel to a receptive stigma. Receptive stigmas will be sticky, catching any passing pollen, whether it be carried by the wind or a visiting animal. Interactions between proteins on the coat of the pollen grain and the stigma enable pollen grains to “recognize” their compatibility. If compatible, then a pollen tube will rapidly grow down through the style and into an ovary.

Growth of the pollen tube is controlled by the pollen tube nucleus, and secretions of digestive enzymes enable it to penetrate into the style. at this time, the generative nucleus of the pollen grain divides by mitosis to form two male gametes. ultimately, the pollen tube will enter the embryo sac. The pollen tube nucleus degenerates and the two male gametes enter the embryo sac through the pollen tube.

one male gamete will fuse with the egg cell, and the other with the fusion nucleus to form an

Sorbus intermedia, Swedish whitebeam

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t

he bauer brothers, franz andreas and ferdinand Lukas, were accomplished botanical artists, although franz was less well known than his much- traveled and renowned brother. They were born in feldsberg, Moravia, now Valtice in the czech Republic, franz in 1758 and ferdinand in 1760. Their father was the court painter to the prince of Liechtenstein, and consequently

they were surrounded by art and paintings from an early age.

Their father died a year after ferdinand was born, and the brothers (including the eldest, Joseph anton) were placed in the custody of father Norbert boccius, abbot of feldsberg, who was a physician and a botanist. together, while still in their teens, the three brothers recorded all the plants and flowers in the monastery garden and produced more than 2,700 watercolor paintings of plant specimens. Their work illustrated a remarkable fourteen-volume book, Liber Regni Vegetabilis (book of the plant Kingdom) or the Codex Liechtenstein. under boccius’ guidance, ferdinand in particular became an astute observer and lover of nature.

In 1780, franz and ferdinand went to Vienna to work for baron Nikolaus Joseph von Jacquin, who

was a renowned botanist and artist, director of the Royal botanical Garden at schönbrunn palace, and professor of botany and chemistry at the university of Vienna. There they were introduced to the Linnaean taxonomic system and the use of microscopy to record fine detail, perfected their skills as botanical illustra- tors, and concentrated on exact observation of plants.

They developed an extraordinary attention to detail that later became their hallmark. The careers of the two brothers then diversified.

In 1788, franz traveled to england, became known as francis, and settled at Kew. He worked at the Royal botanic Gardens, Kew, for more than forty years and was given the title botanick painter to His Majesty, under the sponsorship of sir Joseph Hooker. His illustrations were a valuable scientific record of the newly discovered plants from around the world that were introduced to Kew, where they were grown and studied for the first time in a scientific manner. unlike his brother, he did not want to travel and became more interested in the science and botany of the plants he studied.

franz was elected a fellow of the Linnean society and became a fellow of britain’s Royal society. He died at Kew in 1840.

Fr a n z A n d r e a s B au e r

( 1 7 5 8 – 1 8 4 0 )

Fe r d i n a n d Lu k a s B au e r

( 1 7 6 0 – 1 8 2 6 )

franz andreas bauer (above) and his brother ferdinand spent their lives illustrating plants for books and collections.

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ferdinand went on to become the more famous botanical artist of the two. He traveled with botanists and explorers to record plants in their natural habitats and in the context of the local natural history.

In 1784, ferdinand accompanied John sibthorpe, a botanist and professor from oxford university, on his travels to Greece. This resulted in the publication of Flora Graeca, which is illustrated throughout with bauer’s magnificent artworks of the Greek flora.

He then traveled to australia on HMs Investigator, accompanying sir Joseph banks’ botanist, Robert brown, as botanical draughtsman on banks’ recom- mendation. bauer made around 1,300 drawings of the plants and animals that were seen and collected during the voyage. His colored artworks revealed the wonders of the australian flora and fauna and some

of the paintings were published as engravings in Illustrationes Florae Novae Hollandiae. This was the

first detailed account of the natural history of the australian continent.

When HMs Investigator set sail to return to britain, bauer remained in sydney and took part in further expeditions to New south Wales and to Norfolk Island.

He returned to austria in 1814 and continued to work for english publications including aylmer bourke Lambert’s A Description of the Genus Pinus and illustrations of Digitalis for John Lindley. He lived near the schönbrunn botanical Garden and spent his time painting and making excursions into the austrian alps. He died in 1826.

several australian plant species were named for ferdinand bauer, and the genus Bauera and cape bauer on the australian coast were also named for him.

The standard author abbreviation f. L. bauer is used to indicate him as the author when citing botanical names of plants.

Erica massonii, Masson’s heath

This illustration by franz andreas bauer was used in Delineations of Exotick Plants cultivated in the Royal Garden at Kew. It shows

botanical characteristics displayed according to the Linnean system. Thapsia garganica,Spanish turpeth root

one of ferdinad bauer’s many magnificent artworks of Greek flora used to illustrate the book Flora Graeca.

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b o t a N y f o R G a R d e N e R s

The mechanisms of plant evolution are the

In document DEPARTAMENTO DE FÍSICA Y QUÍMICA. Programación del curso 2021/22 (página 49-60)