Writing about gardens takes a variety of literary forms, ranging from instructional manuals on horticulture and garden design, to essays on gardening, to novels. Garden writing has been published in English since at least the 16th century. Atkinson suggests a two-part division of garden writing, at least in the 19th century. On the one hand, she notes, some garden writers produced utilitarian guides on garden maintenance and horticulture. On the other hand, garden writing also included higher-brow works on the "pleasures of landscape aesthetics". British garden writers are just about able to cover differences in regional climates with the odd reference to "hilly" or "northern" districts, and issue general advice for the whole country; the great majority are based in Southern England. This polite fiction is not tenable for the US and Canada, and much garden writing is regional, taking into account the very different ranges of temperature and rainfall. Early history Early writing, in Latin and Greek, is nearly always more concerned with agriculture, the main element of the economy, than gardening, and there is no surviving single classical authority on techniques of gardening who has the position of, for example, Vitruvius in architecture. Dioscurides is the leading author of herbal literature, with a mainly medical purpose, and much more about how to use and identify plants than how to grow them. After being unavailable in Christian Europe in the Early Middle Ages, he became known again through Arab manuscripts, and then remained the most respected herbal until the 18th century, though even by 1750 only some 400 of the plants he described had been identified and collected. In medieval manuscripts he was often combined with "Apuleius", a late Roman translation of ancient Greek herbal material, revived in England from the 11th century. The important theologian Albertus Magnus in his De vegetabilibus et plantis (c. 1260) rewrites De Plantis, a book then wrongly believed to be by Aristotle. This is a fundamental philosophical enquiry into the nature of plants, only peripherally concerned with how to grow them. But he does recognize and describe gardens with a large element of purely ornamental planting. The Italian Piero de' Crescenzi's, Ruralium Commodorum Liber (c. 1305) is the most important practical medieval work, still mostly about agriculture, and drawing heavily on classical sources. His experience came from buying a country estate, as a successful lawyer. The first significant text in English is a