Report of the Michigan Academy of Science Volume 12 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1910 Excerpt: ...its life cycle; and as the teleuto spores germinate immediately upon reaching maturity, the question of the wintering over has been one feature most prominently of interest. It is with regard to the wintering over, from year to year, that further observations led me to present this brief paper before the Academy. This rust seems to be distinctly on the increase in our locality, but this need give no alarm for the reason that the plants likely to be infested by the fungus, are of little economic importance. In fact, if we leave out of consideration the ornamental plant, Hollyhock, we might say of no economic importance. The common mallow of gardens and waste places around yards and buildings is generally considered something of a noxious weed, and this is the plant most commonly affected. The rust, however, is likely to infest other plants of the mallow family, particularly the following genera including: Malva, Althaea, Malvastrum, Sidalcea, Malope, and Abutilon. The following genera, though growing side by side in the Botanic Garden at the College, were free from the disease: Anoda, Hibiscus, Napaea and Sida. A few of the species of those genera mentioned above as susceptible to the disease, are considered of value as ornamental plants, especially in the east, consequently the rust is of some importance from the economic side, and it would seem to be worth while to make some effort' toward checking it. This will be suggested in the life history here given. Life History: The spores germinate immediately, i. e., without any period of rest, producing a promycelium on which are developed a few sporidia (promycelial spores). This takes about two or three days. The sporidia also germinate as soon as mature and send out an infective mycelium which, under suitable...