Five-needle Pines Research Articles

Lophodermella arcuata . [Descriptions of Fungi and Bacteria

Abstract A description is provided for Lophodermella arcuata . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Pinus albicaulis, Pinus flexilis, Pinus lambertiana, Pinus monticola . DISEASES: Needle cast of five-needle pines. Ascomata are reported to develop rapidly on first-year needles, which turn brown for their entire length in spring. Ascospores are released in July and August, and infect needles which are 2-to 5-months old. Most needles are cast by September of their second year, so that the life-cycle is completed in 15-16 months. On P. monticola the fungus affects mainly the middle and upper crowns of pole-size to mature trees (40, 131). In P. flexilis stands, only occasional isolated trees are affected. The upper crown of diseased trees is thin, with often only the current year's needles present. On P. lambertiana , most trees in two plantations become infected, and both terminal and radial growth reduced (62, 418). The effect of disease on radial growth may, however, be confounded by drought effects. The disease has been considered unimportant in natural stands. GEOGRAPHICAL DISTRIBUTION: USA (California, Colorado, Idaho, Montana, Oregon). TRANSMISSION: By airborne ascospores in wet or humid conditions. Ascospores which have germinated while still within the ascus have been observed in dried preserved herbarium specimens.

Late Tertiary Plant Macrofossilsf from Localities in Arctic/Subarctic North America: A Review of the Data

Bryophyte and vascular plant fossils occur at many late Tertiary sites in Alaska and northern Canada. A number of these floras are received here. The oldest flora, possibly of late Early Miocene age, is probably the one from the Mary Sachs gravel at Duck Hawk Bluffs, Banks Island. The youngest are of early Quaternary age. The floras are of several types. The youngest (Cape Deceit Formation) contains only plants that grow in the Arctic and Subarctic today. The Meighen Island Beaufort Formation contains a few extinct taxa (Aracites globosa) and fossil plants, such as Sambucus, Comptonia, and Physocarpus, that are not found in the present subarctic and arctic regions of North America. Some of these floras also contain fossils of a five-needle pine that may represent the Japanese Stone pine (Pinus pumila). A third group of floras, from Cone Bluff and Lava Camp, Alaska, usually contains more extinct plants (Epipremnum crassum, Decodon and cf. Paliurus) as well as fossils of pines in the subsection Cembrae. The Mary Sachs gravel flora, with taxa such as Metasequoia, Glyptostrobus, Taxodium, Juglans, and Liriodendron, stands apart from all three of the above-mentioned floral types. The Mary Sachs gravel flora represents mixed coniferous and hardwood forests. Most of the other floras represent coniferous forests that were floristically richer than present boreal forest. Some of the richness is due to taxa now found only in Eurasia. The Meighen Island Beaufort flora and some of those from the high-level alluvium on Ellesmere Island represent forest tundra. Several lines of evidence show that the Beaufort Formation on Meighen Island in the Canadian Arctic is about 3 million years old. Several of the younger floras contain abundant, well-preserved bryophyte fossils. Unlike the vascular plants, all of them represent extant species.

Permineralized Pinaceous Leaves from the Upper Cretaceous of Hokkaido

Three fragments of fascicles of a possible five-needle pine are described from the Upper Cretaceous Yezo Group (Santonian/Senonian) of Hokkaido. Specimens from the Omakizawa, Oyubari, Yubari City, the Koyanozawa, Ikushumbetsu, Mikasa City, and the Sankebetsugawa, Haboro are preserved in calcium carbonate nodules containing abundant ammonites. Leaves borne in apparent fascicles of five measure 0.7–0.8 mm in radial and 0.8–1.0 mm in tangential diam and are represented by short fragments of isolated needles. Thick-walled epidermal cells on these amphistomatic leaves resemble the underlying uniform hypodermis. Two external resin canals are situated near the lateral corners toward the adaxial surface. Only slightly plicate mesophyll cells in a layer one to two cells thick border on an elliptical endodermis with thickened outer cell walls. Two to three layers of transfusion tissue surround the double vascular strand. Two vascular bundles are separated by one cell layer of sclerenchyma fibers. Small patches of abaxial and adaxial sclerenchyma fibers have also been observed. Leaves most closely resemble those of Pinus leiophylla Schl. et Cham. Subgenus Pinus, Section Pinea, Subsection Leiophyllae and P. montezumae Lamb. Subgenus Pinus, Section Pinus, Subsection Ponderosae and are described as a new species P. hokkaidoensis sp. nov. Stockey and Ueda. Close anatomical comparisons are made with this leaf and previously described permineralized Upper Cretaceous pine needles from Hokkaido and eastern North America.

Pathological anatomy of five-needle pines infected with Cronartium ribicola FISCHER ex RABENH (II) Morphology of peridermia formed on one- and two-year-old stems and shoots, and histological responses in the bark tissues of host trees

Pathological anatomy of five-needle pines infected with Cronartium ribicola FISCHER ex RABENH (II) Morphology of peridermia formed on one- and two-year-old stems and shoots, and histological responses in the bark tissues of host trees

Histochemistry of RNA during pollen tube growth and early embryogenesis in eastern white pine

Pinus strobus trees were crossed with pollen of the same species and with pollen of two non-crossable five-needle pines. Ovules were collected and sectioned during various phases of pollen tube growth and early embryogenesis. RNA was then localized by two staining methods coupled with enzymatic extraction. A layer of cells in the nucellus accumulates RNA in association with the growing pollen tube. The prothallial cells which will lyse to form the corrosion cavity are more rich in RNA than the surrounding cells both before fertilization and in the proembryo stages. Nucleolar RNA increases throughout the prothallium after suspensor elongation. The embryonic apex stains more intensely than do the suspensors, and intraspecific embryos stain more intensely than embryos of inviable hybrids.

THE EASTERN PINE-SHOOT BORER, EUCOSMA GLORIOLA (LEPIDOPTERA: TORTRICIDAE), IN NORTH AMERICA

AbstractEucosma gloriola Heinrich is distinguished from E. sonomana Kearfott, a closely related species, by using differences in morphology and distribution. E. gloriola is notably smaller in alar expanse and in size of male genitalia. The distribution of E. gloriola follows closely the natural range of eastern white pine (Pinus strobus L.), while E. sonomana follows that of ponderosa pine (P. ponderosa Laws.).Eucosma gloriola overwinters in the pupal stage in the soil. Adults emerge from late April to mid-May in eastern and southern areas, and from late April to early June in northern areas. The insect passes through five larval instars within a pine shoot. Larvae emerge from shoots and drop to the ground in early July in eastern and southern areas, and somewhat later in northern areas.Symptoms of attack and injury by E. gloriola in two- and five-needle pines are distinct from those of other eastern shoot and tip moths. The destruction of leaders is the most important injury since stunted and deformed trees result from repeated attack.Large-scale chemical control methods as required in reforestation plantings of Christmas trees are difficult to achieve. Glypta sp. was the most abundant of five parasites reared from the eastern pine-shoot borer.

Measuring the Local Distribution of Ribes

Blister rust control, as is well known, consists of the destruction of the alternate hosts, currant and gooseberry plants (Ribes spp.), in and near stands of susceptible five-needle or white pines. The ribes population must be reduced to a very small figure in order to accomplish the protection of the pine. Making sure, either before or after eradication, that the ribes in a stand are so few as not to menace the pine involves systematically checking the stand and its environs. The checking procedure used in the Rocky Mountain and Pacific Coast States is described by Harris ('41). The checkers are usually required to cover either 4 per cent or 5 per cent of the land area under examination and to report the number and location of the ribes discovered. Considerable attention has recently been given to the problem of evaluating the sampling data obtained by 4 per cent, 5 per cent, and 8 per cent checks, respectively. Their significance involves three phases: (1) The reliability of the checking record as an estimate of the total ribes population on unit areas of various sizes; (2) determining how ac-

The Vegetative Propagation of Eastern White Pine and other Five-Needled Pines

The Vegetative Propagation of Eastern White Pine and other Five-Needled Pines