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Torreya Taxifolia Seed Anatomy
''Torreya'' is a genus of conifers comprising six or seven species placed in the family Taxaceae, though sometimes formerly placed in Cephalotaxaceae. Four species are native to eastern Asia; the other two are native to North America. They are small to medium-sized evergreen trees reaching 5–20 m, rarely 25 m, tall. Common names include nutmeg yew. The genus is one example of the Arcto-Tertiary Geoflora in paleoecology. The pattern of highly disjunct distribution of geographic ranges of the species within such a genus spans temperate plant zones of continents in the Northern Hemisphere. This geographic pattern is attributed to genus origins in much warmer times of the Tertiary Period, when zones of temperate climate were found in poleward latitudes whereby land connections facilitated range expansions and migrations of plants between Asia and North America and sometimes between Europe and North America. The leaves are spirally arranged on the shoots, but twisted at the base ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Eocene
The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope 13C in the atmosphere was exceptionally low in comparison with the more common isotope 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay. As with other geologic periods, the strata that define the start and end of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Hemisphere
The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's North Pole. Owing to Earth's axial tilt of 23.439281°, winter in the Northern Hemisphere lasts from the December solstice (typically December 21 UTC) to the March equinox (typically March 20 UTC), while summer lasts from the June solstice through to the September equinox (typically on 23 September UTC). The dates vary each year due to the difference between the calendar year and the astronomical year. Within the Northern Hemisphere, oceanic currents can change the weather patterns that affect many factors within the north coast. Such events include El Niño–Southern Oscillation. Trade winds blow from east to west just above the equator. The winds pull surface water with them, creating currents, which flow westward due to the Coriolis e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Torrey
John Torrey (August 15, 1796 – March 10, 1873) was an American botany, botanist, chemist, and physician. Throughout much of his career, he was a teacher of chemistry, often at multiple universities, while he also pursued botanical work, focusing on the flora of North America. His most renowned works include studies of the New York flora, the Mexican Boundary, the Pacific railroad surveys, and the uncompleted ''Flora of North America''. Biography Torrey was born in New York City, the second child of Capt. William and Margaret (née Nichols) Torrey.Robbins, C. C. (1968). John Torrey (1796–1873), His Life & Times. ''Bulletin of the Torrey Botanical Club''. Vol. 95, No. Nov. 6–Dec. 1968, 515–645. Torrey Botanical Club, New York. He showed a fondness for mechanics, and at one time planned to become a machinist. When he was 15 or 16, his father received an appointment to the state prison at Greenwich Village, New York, where he was tutored by Amos Eaton, then a pri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Squirrel
Squirrels are members of the family Sciuridae, a family that includes small or medium-size rodents. The squirrel family includes tree squirrels, ground squirrels (including chipmunks and prairie dogs, among others), and flying squirrels. Squirrels are indigenous to the Americas, Eurasia, and Africa, and were introduced by humans to Australia. The earliest known fossilized squirrels date from the Eocene epoch, and among other living rodent families, the squirrels are most closely related to the mountain beaver and to the dormice. Etymology The word ''squirrel'', first attested in 1327, comes from the Anglo-Norman which is from the Old French , the reflex of a Latin word , which was taken from the Ancient Greek word (; from ) 'shadow-tailed', referring to the long bushy tail which many of its members have. The native Old English word for the squirrel, , survived only into Middle English (as ) before being replaced. The Old English word is of Common Germanic origin, cognat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north toward the East China Sea, Philippine Sea, and Taiwan in the south. Japan is a part of the Ring of Fire, and spans Japanese archipelago, an archipelago of List of islands of Japan, 6852 islands covering ; the five main islands are Hokkaido, Honshu (the "mainland"), Shikoku, Kyushu, and Okinawa Island, Okinawa. Tokyo is the Capital of Japan, nation's capital and largest city, followed by Yokohama, Osaka, Nagoya, Sapporo, Fukuoka, Kobe, and Kyoto. Japan is the List of countries and dependencies by population, eleventh most populous country in the world, as well as one of the List of countries and dependencies by population density, most densely populated and Urbanization by country, urbanized. About three-fourths of Geography of Japan, the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nut (fruit)
A nut is a fruit consisting of a hard or tough nutshell protecting a kernel which is usually edible. In general usage and in a culinary sense, a wide variety of dry seeds are called nuts, but in a botanical context "nut" implies that the shell does not open to release the seed (indehiscent). Most seeds come from fruits that naturally free themselves from the shell, but this is not the case in nuts such as hazelnuts, chestnuts, and acorns, which have hard shell walls and originate from a compound ovary. The general and original usage of the term is less restrictive, and many nuts (in the culinary sense), such as almonds, pecans, pistachios, walnuts, and Brazil nuts, are not nuts in a botanical sense. Common usage of the term often refers to any hard-walled, edible kernel as a nut. Nuts are an energy-dense and nutrient-rich food source. Botanical definition A seed is the mature fertilised ovule of a plant; it consists of three parts, the embryo which will develop into a ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drupe
In botany, a drupe (or stone fruit) is an indehiscent fruit in which an outer fleshy part (exocarp, or skin, and mesocarp, or flesh) surrounds a single shell (the ''pit'', ''stone'', or '' pyrena'') of hardened endocarp with a seed (''kernel'') inside. These fruits usually develop from a single carpel, and mostly from flowers with superior ovaries (polypyrenous drupes are exceptions). The definitive characteristic of a drupe is that the hard, lignified stone is derived from the ovary wall of the flower. In an aggregate fruit, which is composed of small, individual drupes (such as a raspberry), each individual is termed a drupelet, and may together form an aggregate fruit. Such fruits are often termed ''berries'', although botanists use a different definition of ''berry''. Other fleshy fruits may have a stony enclosure that comes from the seed coat surrounding the seed, but such fruits are not drupes. Flowering plants that produce drupes include coffee, jujube, mango, oli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seed
A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosperm plants. Seeds are the product of the ripened ovule, after the embryo sac is fertilized by sperm from pollen, forming a zygote. The embryo within a seed develops from the zygote, and grows within the mother plant to a certain size before growth is halted. The seed coat arises from the integuments of the ovule. Seeds have been an important development in the reproduction and success of vegetable gymnosperm and angiosperm plants, relative to more primitive plants such as ferns, mosses and liverworts, which do not have seeds and use water-dependent means to propagate themselves. Seed plants now dominate biological niches on land, from forests to grasslands both in hot and cold climates. The term "seed" also has a general me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollen
Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophytes during the process of their movement from the stamens to the pistil of flowering plants, or from the male cone to the female cone of gymnosperms. If pollen lands on a compatible pistil or female cone, it germinates, producing a pollen tube that transfers the sperm to the ovule containing the female gametophyte. Individual pollen grains are small enough to require magnification to see detail. The study of pollen is called palynology and is highly useful in paleoecology, paleontology, archaeology, and forensics. Pollen in plants is used for transferring haploid male genetic material from the anther of a single flower to the stigma of another in cross-pollination. In a case of self-pollination, this process takes place from the anth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conifer Cone
A conifer cone (in formal botany, botanical usage: strobilus, plural strobili) is a seed-bearing organ on gymnosperm plants. It is usually woody, ovoid to globular, including scales and bracts arranged around a central axis, especially in conifers and cycads. The cone of Pinophyta (conifer clade) contains the plant sexuality, reproductive structures. The woody cone is the female cone, which produces seeds. The male cone, which produces pollen, is usually herbaceous plant, herbaceous and much less conspicuous even at full maturity. The name "cone" derives from Greek ''konos'' (pine cone), which also gave name to the cone (geometry), geometric cone. The individual plates of a cone are known as ''scales''. The ''umbo'' of a conifer cone refers to the first year's growth of a seed scale on the cone, showing up as a protuberance at the end of the two-year-old scale. The male cone (microstrobilus or pollen cone) is structurally similar across all conifers, differing only in small wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torreya Guardians
The Torreya Guardians is a self-organized group of conservationists dedicated to facilitating the assisted migration of the Florida torreya by rewilding it further north than its native range in Florida and Georgia. Founded in the early 2000s, the group is often mentioned as an instigator of the assisted migration of forests in North America for conservation and climate adaptation purposes. It is an example of citizen-initiated citizen science. Background The endangered Florida torreya The Florida Torreya (''Torreya taxifolia)'' is an endangered tree of the yew family, Taxaceae, found in the Southeastern United States, at the state border region of northern Florida and southwestern Georgia. ''T. taxifolia'' became one of the first federally listed endangered plant species in the United States in 1984; the IUCN has listed the species as critically endangered since 1998. It is considered "the rarest conifer in North America." In 2010 98% of the mature trees of the species ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plant Sexuality
Plant reproductive morphology is the study of the physical form and structure (the Plant morphology, morphology) of those parts of plants directly or indirectly concerned with sexual reproduction. Among all living organisms, flowers, which are the reproductive structures of flowering plant, angiosperms, are the most varied physically and show a correspondingly great diversity in methods of reproduction. Plants that are not flowering plants (green algae, mosses, Marchantiophyta, liverworts, hornworts, ferns and gymnosperms such as conifers) also have complex interplays between morphological adaptation and environmental factors in their sexual reproduction. The breeding system, or how the sperm from one plant fertilizes the ovum of another, depends on the reproductive morphology, and is the single most important determinant of the genetic structure of nonclonal plant populations. Christian Konrad Sprengel (1793) studied the reproduction of flowering plants and for the first time it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
