Misplaced Pages

#698301

58-462: Rauvolfia (sometimes spelled Rauwolfia ) is a genus of evergreen trees and shrubs , commonly known as devil peppers , in the family Apocynaceae . The genus is named to honor Leonhard Rauwolf . The genus can mainly be found in tropical regions of Africa , Asia , Latin America , and various oceanic islands. The International Code of Nomenclature for algae, fungi, and plants stipulates that

116-617: A broad transition zone from Labrador to northern Alaska. In Labrador, white spruce is not abundant and constitutes less than 5% of the forest, with a range that coincides very closely with that of black spruce but extending slightly further north. The range of white spruce extends westwards from Newfoundland and Labrador, and along the northern limit of trees to Hudson Bay, Northwest Territories, Yukon, and into northwestern Alaska. Across western Canada and Alaska, white spruce occurs further north than black spruce, and, while poplar ( Populus ), willow , and birch may occur along streams well into

174-497: A cold or dry/wet season. Evergreen trees also lose leaves, but each tree loses its leaves gradually and not all at once. Most tropical rainforest plants are considered to be evergreens, replacing their leaves gradually throughout the year as the leaves age and fall, whereas species growing in seasonally arid climates may be either evergreen or deciduous. Most warm temperate climate plants are also evergreen. In cool temperate climates, fewer plants are evergreen. In such climates, there

232-731: A higher soil acidity and lower soil nitrogen content. This is the case with Mediterranean evergreen seedlings, which have unique C and N storages that allow stored resources to determine fast growth within the species, limiting competition and bolstering survival. These conditions favor the growth of more evergreens and make it more difficult for deciduous plants to persist. In addition, the shelter provided by existing evergreen plants can make it easier for younger evergreen plants to survive cold and/or drought. Evergreen plants can have decorative as well as functional uses. In months where most other plants are dormant, evergreens with their sturdy structure, and vibrant foliage are popular choices to beautify

290-539: A landscape. Additionally, evergreens can serve as a windbreak , stopping heat loss from buildings during cold months when placed on the northwest side of a structure. Picea glauca Picea glauca (Moench) Voss., the White Spruce , is a species of spruce native to the northern temperate and boreal forests in Canada and United States , North America. Picea glauca is native from central Alaska all through

348-420: A larger volume of parenchyma and air spaces per unit leaf area. They have larger leaf biomass per unit leaf area, and hence a lower specific leaf area . Construction costs do not differ between the groups. Evergreens have generally a larger fraction of total plant biomass present as leaves (LMF), but they often have a lower rate of photosynthesis. Deciduous trees shed their leaves usually as an adaptation to

406-915: A narrow belt of mixed Norway and white spruces over an extremely exposed hilltop crest at high elevation in northern England, the Norway spruce were "completely dwarfed" whereas the white spruce had reached heights of between 3 and 4.3 m. The age of the belt was not recorded, but adjoining 66-year-old stands may have been of the same vintage. White spruce has also been used as a minor plantation species in England and Scotland. In Scotland, at Corrour, Inverness-shire, Sir John Stirling Maxwell in 1907 began using white spruce in his pioneering plantations at high elevations on deep peat. However, plantations in Britain have generally been unsatisfactory, mainly because of damage by spring frosts after mild weather had induced flushing earlier in

464-436: A smoothly rounded margin. They are green or reddish, maturing to pale brown 4 to 8 months after pollination. The seeds are black, 2 to 3 mm long, with a slender, 5 to 8 mm long pale brown wing. Seeds are small, 2.5 to 5 mm long, oblong, and acute at the base. Determinations of the average number of sound seeds per white spruce cone have ranged from 32 to 130. Common causes of empty seed are lack of pollination , abortion of

522-438: Is a predominance of conifers because few evergreen broadleaf plants can tolerate severe cold below about −26 °C (−15 °F). In addition, evergreen foliage experiences significant leaf damage in these cold, dry climates. Root systems are the most vulnerable aspect of many plants. Even though roots are insulated by soil, which tends to be warmer than average air temperatures, soil temperatures that drop too low can kill

580-715: Is an alkaloid first isolated from R. serpentina and was widely used as an antihypertensive drug Rauvolfia serpentina is declining in the wild due to collection for its medicinal uses. Consequently, it is listed in CITES Appendix II . Rauvolfia vomitoria is a highly invasive species in Hawaiʻi , and is capable of establishing dense monotypic stands. Species include: Evergreen There are many different kinds of evergreen plants, including trees , shrubs , and vines. Evergreens include: The Latin binomial term sempervirens , meaning "always green", refers to

638-490: Is extremely hardy to low temperatures, provided the plant is in a state of winter dormancy . Throughout the greater part of its range, white spruce routinely survives and is undamaged by winter temperatures of −50 °C (−58 °F), and even lower temperatures occur in parts of the range. Boreal Picea are among the few extremely hardy conifers in which the bud primordia are able to survive temperatures down to −70 °C, −94 °F. Especially important in determining

SECTION 10

#1732854819699

696-695: Is not characteristic, except perhaps on shallow mesic organic soils in Saskatchewan and in association with black spruce on organic soils in central Yukon. Podzolized, brunisolic, luvisolic, gleysolic, and regosolic (immature) soils are typical of those supporting white spruce throughout the range of the species. Soils supporting white spruce are most commonly Alfisols or Inceptisols. In the podzol region of Wisconsin, white spruce occurs on loam podzols, podzolized gley loams, strongly podzolized clays, gley-podzol clays, stream-bottom soils, and wood peat. Moist sandy loams also support good growth. On sandy podzols, it

754-543: Is obviously a factor in determining distributions of northern flora . Halliday and Brown suggested that white spruce's northern limit corresponds "very closely" with the July mean monthly isotherm of 10 °C in Ungava, but that the northern limit west of Hudson Bay was south of that isotherm. Other climatic factors that have been suggested as affecting the northern limit of white spruce include: cumulative summer degree days, position of

812-417: Is the forest/prairie interface through Alberta, Saskatchewan, Manitoba, the northern parts of Minnesota and Wisconsin, central Michigan, northeastern New York, and Maine. Sargent and Harlow and Harrar also included Vermont and New Hampshire; and, while Dame and Brooks excluded New York and states further west, they included Massachusetts as far south as Amherst and Northampton, "probably the southern limit of

870-744: Is thin and scaly, flaking off in small circular plates 5 to 10 centimetres (2 to 4 in) across. The crown is narrow – conical in young trees, becoming cylindrical in older trees. The shoots are pale buff-brown, glabrous in the east of the range, but often pubescent in the west, and with prominent pulvini . The leaves are needle-like, 12 to 20 millimetres long, rhombic in cross-section, glaucous blue-green above (hence glauca ) with several thin lines of stomata , and blue-white below with two broad bands of stomata. The cones are pendulous, slender, cylindrical, 3 to 7 cm long and 1.5 cm wide when closed, opening to 2.5 cm broad. They have thin, flexible scales 15  mm long with

928-557: Is tolerated by white spruce. Thrifty stands of white spruce in Manitoba have developed on soils of pH 7.6 at only 10 cm below the surface, and pH 8.4 at 43 cm below the surface; rooting depth in those soils was at least 81 cm. An abundant calcium supply is common to most white spruce locations in New York state. Chlorosis was observed in young white spruce in heavily limed nursery soils at about pH 8.3. Wilde gave 4.7 to 6.5 as

986-557: Is too moist unless soil moisture is stagnant. Soil fertility holds the key not just to white spruce growth but to the distribution of the species. At least moderate fertility is needed for good growth, but white spruce occurs on many sites where nutrient deficiencies depress its growth more than that of black spruce, red spruce, Norway spruce, and the pines generally. Minimum soil-fertility standards recommended for white spruce sufficient to produce 126 to 157 m /ha of wood at 40 years are much higher than for pine species commonly planted in

1044-745: Is usually a minor species. Good development occurs on moist alluvium on the banks of streams and borders of swamps. White spruce makes good growth on well-drained lacustrine soils in Alberta Mixedwoods, on moderately-well-drained clay loams in Saskatchewan,, and on melanized loams and clays (with sparse litter and a dark-coloured organically-enriched mineral horizon) in the Algoma district of Ontario. White spruce becomes less accommodating of soil with increasing severity of climate. The distribution of white spruce in Labrador seems to depend almost entirely on

1102-508: The Black Hills of South Dakota and Wyoming . It is also known as Canadian spruce , skunk spruce , cat spruce , Black Hills spruce , western white spruce , Alberta white spruce , and Porsild spruce . The white spruce is a large evergreen conifer which normally grows to 15 to 30 metres (50 to 100 ft) tall, but can grow up to 40 m (130 ft) tall with a trunk diameter of up to 1 m (3 ft 3 in). The bark

1160-643: The Black Hills on the Wyoming–South Dakota boundary, on the Manitoba–North Dakota boundary, and at Shushan, New York. White spruce is the northernmost tree species in North America, reaching just north of 69°N latitude in the Mackenzie River delta. It grows between sea level and an elevation of 1,520 m (4,990 ft). Its northern distribution roughly correlates to the location of

1218-543: The Boreal , Subalpine, Montane, Columbia, Great Lakes –St. Lawrence, and Acadian Forest Regions, extending into every province and territory. On the west coast of Hudson Bay , it extends to Seal River , about 59°N, "from which the northward limit runs apparently almost directly north-west to near the mouth of the Mackenzie River , or about latitude 68°". Collins and Sumner reported finding white spruce within 13 km of

SECTION 20

#1732854819699

1276-530: The early succession species. Wildfires typically occur every 60 to 200 years, although they have been known to occur as infrequently as every 300 years. White spruce will grow in USDA Growing Zones 3–7, but is not adapted to heat and humidity and will perform poorly in a hot climate. The tree attains its greatest longevity and growth potential in Zones 3–4. Wildlife such as deer, rabbits, and grouse browse

1334-416: The ovule , and insect damage. The average weight per individual seed varies from 1.1 mg to 3.2 mg. Each seed is clasped by a thin wing 2 to 4 times as long as the seed. Seed and wing are appressed to the cone scale. Embryo and megagametophyte are soft and translucent at first; later the endosperm becomes firm and milky white, while the embryo becomes cream-coloured or light yellow. At maturity,

1392-479: The tree line , which includes an isothermic value of 10 °C (50 °F) for mean temperature in July, as well as the position of the Arctic front ; cumulative summer degree days, mean net radiation, and the amount of light intensities also figure. White spruce is generally found in regions where the growing season exceeds 60 days annually. The southern edge of the zone in which white spruce forms 60% or more of

1450-903: The Arctic coast in the Firth Valley , Yukon, at about 69°30′ N, 139°30′ W. It reaches within 100 km of the Pacific Ocean in the Skeena Valley , overlapping with the range of Sitka spruce ( Picea sitchensis ), and almost reaching the Arctic Ocean at latitude 69° N in the District of Mackenzie , with white spruce up to 15 m high occurring on some of the islands in the Delta near Inuvik . The wide variety of ecological conditions in which 4 Quebec conifers, including white spruce, are able to establish themselves,

1508-464: The Arctic front in July, mean net radiation especially during the growing season, and low light intensities. Topography, soil conditions, and glaciation may also be important in controlling northern limits of spruce. The southern limit of distribution of white spruce is more complex. From east of the main range of coastal mountains in British Columbia, the southern continuous limit of white spruce

1566-541: The Lake States (Wilde 1966): 3.5% organic matter, 12.0 meq/100 g exchange capacity, 0.12% total N, 44.8 kg/ha available P, 145.7 kg/ha available K, 3.00 meq/100 g exchangeable Ca, and 0.70 meq/100 g exchangeable Mg. Forest floors under stands dominated by white spruce respond in ways that vary with site conditions, including the disturbance history of the site. Composition, biomass , and mineral soil physical and chemical properties are affected. In Alaska,

1624-497: The accumulation of organic layers (to greater thicknesses in mature stands of spruce than those in hardwood stands on similar sites) leads to decreased soil temperatures, in some cases leading to the development of permafrost. Acidity of the mineral soil sampled at an average depth of 17 cm in 13 white spruce stands on abandoned farmland in Ontario increased by 1.2 pH units over a period of 46 years. A considerable range of soil pH

1682-524: The approximate optimum range of pH for white spruce in Wisconsin, but optimum growth seems possible at pH levels up to 7.0 and perhaps higher. Alluvium on the floodplains of northern rivers shows pH levels from 5.0 to 8.2. High-lime ecotypes may exist, and in Canada Forest Section B8 the presence of balsam poplar and white spruce on some of the moulded moraines and clays seems to be correlated with

1740-476: The area in which they reside. The excellent water economy within the evergreen species is due to high abundance when compared to deciduous species. Whereas deciduous trees lose nutrients whenever they lose their leaves. In warmer areas, species such as some pines and cypresses grow on poor soils and disturbed ground. In Rhododendron , a genus with many broadleaf evergreens, several species grow in mature forests but are usually found on highly acidic soil where

1798-451: The character of the soil, and between the southwestern shores of Hudson Bay and the northeastern regions of Saskatchewan, white spruce is confined to very local physiographic features, characterized by well-drained or fertile soils. On dry, deep, outwash deposits in northern Ontario, both white spruce and aspen grow slowly. But, broadly, white spruce is able to tolerate considerable droughtiness of sites that are fertile, and no fertile site

Rauvolfia - Misplaced Pages Continue

1856-468: The closely related Engelmann spruce found further south in the Rocky Mountains. White spruce also hybridises readily with the closely related Sitka spruce where they meet in southern Alaska and northwestern British Columbia; this hybrid is known as Picea × lutzii . White spruce has a transcontinental range in North America. In Canada, its contiguous distribution encompasses virtually the whole of

1914-405: The considerable lime content of these materials, while calcareous soils are favourable sites for northern outliers of white spruce. Mature stands of white spruce in boreal regions often have well-developed moss layers dominated by feather mosses, e.g., Hylocomium splendens , Pleurozium schreberi , Ptlium crista-castrensis , and Dicranum , rather than Sphagnum . The thickness of

1972-469: The distribution is inhibited by white spruce's cold requirement. As an exotic, white spruce is widespread but uncommon. It was introduced into England and parts of continental Europe in or soon after the year 1700, into Denmark about 1790, and into Tasmania and Ceylon shortly before 1932. Nisbet noted that firmly-rooted white spruce served very well to stabilize windswept edges of woods in Germany. In

2030-530: The east, across western and southern/central Canada to the Avalon Peninsula in Newfoundland, Quebec , Ontario and south to Montana , North Dakota , Minnesota , Wisconsin, Michigan, Upstate New York and Vermont, along with the mountainous and immediate coastal portions of New Hampshire and Maine, where temperatures are just barely cool and moist enough to support it. There is also an isolated population in

2088-546: The evergreen nature of the plant, for instance: The longevity of individual leaves in evergreen plants varies from a few months to several decades (over 30 years in the Great Basin bristlecone pine ). Japanese umbrella pine is unique in that it has its own family of which it is the only species. Evergreen and deciduous species vary in a range of morphological and physiological characters. Generally, broad-leaved evergreen species have thicker leaves than deciduous species, with

2146-465: The far north, the total depth of the moss and underlying humus is normally between 25 and 46 cm (10 and 18 in), although it tends to be shallower when hardwoods are present in the stand. White spruce grows in soils with pH values of 4.7–7.0, although they have been found in soils as acidic as 4.0 in subalpine fir forests in the Northwest Territories. A presence of calcium in

2204-506: The foliage during the winter. White spruce occurs on a wide variety of soils, including soils of glacial, lacustrine, marine, and alluvial origins; overlying basic dolomites, limestones and acidic Precambrian and Devonian granites and gneisses; and Silurian sedimentary schists, shales, slates, and conglomerates. The wide range of textures accommodated includes clays, even those that are massive when wet and columnar when dry, sand flats, and coarse soils. Its occurrence on some organic soils

2262-622: The genus name was established by Carl Linnaeus in his 1753 book Species Plantarum , which cites his earlier description which states in Botanical Latin that the name is dedicated "to Leonhard Rauwolf": " Leon. Rauvolfio ". Although some subsequent authors hypercorrected the Classical Latin letter "v" to a modern "w", this is not accepted by the code of nomenclature. Rauvolfia serpentina , commonly known as Indian snakeroot or sarpagandha , contains many indole alkaloids . Reserpine

2320-527: The late summer or early fall of the year of formation. Cones open at moisture contents of 45% to 70% and specific gravities of 0.6 to 0.8. Weather affects both the initiation and pattern of seed dispersal, but cone opening and the pattern of seed dispersal can vary among trees in the same stand. Even after dispersal has begun, cold, damp weather will cause cone scales to close; they will reopen during dry weather. Most seed falls early rather than late, but dispersal may continue through fall and winter and even into

2378-408: The moss–organic layer commonly exceeds 25 cm in the far north and may approach twice that figure. The mosses compete for nutrients and have a major influence on soil temperatures in the rooting zone. Permafrost development in parts of Alaska, Yukon, and the Northwest Territories is facilitated by the insulative organic layer (Viereck 1970a, b, Gill 1975, Van Cleve and Yarie 1986). White spruce

Rauvolfia - Misplaced Pages Continue

2436-439: The nearest seed source. The root system of white spruce is highly variable and adaptable, responding to a variety of edaphic factors, especially soil moisture , soil fertility , and mechanical impedance. On soils that limit rooting depth, the root system is plate-like, but it is a common misconception to assume that white spruce is genetically constrained to develop plate-like root systems irrespective of soil conditions. In

2494-447: The next growing season. Seed dispersal occurs mainly in late summer or early fall. White spruce seed is initially dispersed through the air by wind. Both the initiation and pattern of seed dispersal depend on the weather, but these can vary among trees in the same stand. Small amounts of white spruce seed are normally dispersed beyond 100 m from the seed source, but exceptionally seeds have been found more than 300–400 m from

2552-643: The northern edge of continuous forest in central Canada at Ennadai Lake, about 60°45′ N, 101°’W, just north of the northwest corner of Manitoba. Bryson et al. noted that the forest retained "the same general characteristics as when it was first described [by Tyrrell ] in 1896". Collins and Sumner reported finding white spruce within 13 km of the Arctic coast in the Firth valley, Yukon, at about 69°30′ N, 139°30′ W, and Sargent noted that white spruce in Alaska "reached Behring Strait in 66°44′ N". Climate, especially temperature,

2610-493: The nursery, or naturally in the forest, white spruce usually develops several long 'running' roots just below the ground surface. The structure of the tracheids in the long lateral roots of white spruce varies with soil nitrogen availability. White spruce can live for several hundred years, with an estimated average lifespan of 250 to 300 years. Slow-growing trees in rigorous climates are also capable of great longevity. White spruce 6 to 10 m (20 to 33 ft) high on

2668-423: The nutrients are less available to plants. In taiga or boreal forests , it is too cold for the organic matter in the soil to decay rapidly, so the nutrients in the soil are less easily available to plants, thus favoring evergreens. In temperate climates, evergreens can reinforce their own survival; evergreen leaf and needle litter has a higher carbon-nitrogen ratio than deciduous leaf litter , contributing to

2726-448: The plant. The exact temperature which evergreen roots can handle depends on the species, for example, Picea Glauca (White Spruce) roots are killed at −10 °F (−23 °C). In areas where there is a reason for being deciduous, e.g. a cold season or dry season, evergreen plants are usually an adaptation of low nutrient levels. Additionally, they usually have hard leaves and have an excellent water economy due to scarce resources in

2784-545: The range except the southernmost and southeasternmost parts. By itself, or with black spruce and tamarack ( Larix laricina ), white spruce forms the northern boundary of tree-form growth. White spruce up to 15 m in height occur at 69°N on islands in the Mackenzie Delta near Inuvik in the Northwest Territories. Hustich (1966) depicted Picea spp. as forming the northernmost limit of tree growth in North America. The arctic or northern timberline in North America forms

2842-472: The response of white spruce to low temperatures is the physiological state of the various tissues, notably the degree of "hardening" or dormancy. A natural progression of hardening and dehardening occurs in concert with the seasons. While different tissues vary in ability to tolerate exposure to stressful temperatures, white spruce, as with woody plants in general, has necessarily developed sufficient winter hardiness in its various tissues to enable them to survive

2900-603: The season. However, the species is held in high regard in the Belgian peat region, where it grows better than do the other spruces. White spruce is a climax canopy tree in the boreal forests of Canada and Alaska. It generally occurs on well-drained soils in alluvial and riparian zones , although it also occurs in soils of glacial and lacustrine origin. The understory is dominated by feather mosses ( Hylocomium splendens , Pleurozium schreberi , Ptilium crista-castrensis ) and fork mosses , and occasionally peat moss . In

2958-559: The shore of Urquhart Lake, Northwest Territories, were found to be more than 300 years old. The bark of mature white spruce is scaly or flaky, grey-brown or ash-brown, but silvery when freshly exposed. Resin blisters are normally lacking, but the Porsild spruce Picea glauca var. porsildii Raup has been credited with having smooth resin-blistered bark. White spruce bark is mostly less than 8 mm and not more than 9.5 mm thick. Isorhapontin can be found in spruce species such as

SECTION 50

#1732854819699

3016-441: The soil is common to white spruce found in northern New York. White spruce most commonly grows in the soil orders of Alfisols and Inceptisols . Soil properties such as fertility, temperature, and structural stability are partial determinants of the ability of white spruce to grow in the extreme northern latitudes. In the northern limits of its range, white spruce is the climax species along with black spruce; birch and aspen are

3074-490: The species" in that area. Nisbet gave the range of white spruce as extending to "Carolina", but he did not recognize red spruce as a species and presumably included it with white spruce. Towards the southern parts of its range, white spruce encounters increasingly effective ecological competition from hardwoods , some of which may reinforce their growth-rate or sprouting competitiveness with allelopathic depredation of coniferous regeneration . Further southward extension of

3132-695: The testa darkens rapidly from light brown to dark brown or black. Mature seeds "snaps in two" when cut by a sharp knife on a firm surface. White spruce cones reach their maximum size after 800 GDD . Cone moisture content decreases gradually after about 1000 GDD. Cone colour also can be used to help determine the degree of maturation, but cones may be red, pink or green. Collection and storage dates and conditions influence germination requirements and early seedling growth. A bushel (35 L) of cones, which may contain 6500 to 8000 cones, yields 6 to 20 ounces (170 to 570 g) of clean seed. Seed dispersal begins after cone scales reflex with cone maturation in

3190-772: The total stand corresponds more or less to the July isotherm of 18 °C (64 °F) around the Great Lakes; in the Prairie Provinces its limit is north of this isotherm. During the summer solstice , day length values range from 17 hours at its southern limits to 24 hours above the Arctic Circle . One of the hardiest conifers, white spruce in parts of its range withstands mean daily January temperature of −6.7 °C (19.9 °F) and extreme minimum temperatures as low as −56.5 °C (−69.7 °F); minimum temperatures of −50 °C (−58 °F) are general throughout much of

3248-406: The tundra beyond the limits of spruce, the hardwoods are usually no more than scrub. Spruce characteristically occurs in fingers of tree-form forest, extending far down the northern rivers and as scattered clumps of dwarfed "bush" spruce on intervening lands. In Manitoba, Scoggan noted that the northernmost collection of white spruce was at latitude 59°48’N, but Bryson et al. found white spruce in

3306-767: The white spruce. P. glauca has three different genomes; a nuclear genome, a mitochondrial genome, and a plastid (i.e. chloroplast) genome. The large (20 Gbp) nuclear genome of P. glauca (genotype WS77111) was published in 2015, and the organellar (plastid and mitochondrial) genomes (genotype PG29) were published in SD Jackman et al. 2015. The plastid genome of P. glauca (genotype WS77111) has also been published. Several geographical varieties have been described, but are not accepted as distinct by all authors. These comprise, from east to west: The two western varieties are distinguished by pubescent shoots, and may be related to extensive hybridisation and intergradation with

3364-735: Was noted by Lafond, but white spruce was more exacting than black spruce . In the United States, the range of white spruce extends into Maine, Vermont, New Hampshire, New York, Michigan, Wisconsin, Minnesota, and Alaska, where it reaches the Bering Strait in 66°44′ N" at Norton Bay and the Gulf of Alaska at Cook Inlet. Southern outliers have been reported in southern Saskatchewan and the Cypress Hills of southwestern Saskatchewan and southeastern Alberta, northwestern Montana, south-central Montana, in

#698301