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Miss Chen
2017年12月22日
Miss Chen

平安树真实名字为兰屿肉桂，平安树只为其别称，其树属于常绿的樟科植物，原产于我国台湾的兰屿岛。平安树枝杆端庄，呈黄绿色状，光滑而无茸毛。平安树叶片一般相对而生亦或近对而生，叶子的表面为亮绿色，并有类似金属的光泽，背面则是灰绿色。平安树的养殖作用有很多种，它即可用来做盆栽景观植物，又可以是非常漂亮的园景植物，此外，它还有净化室内空气，吸收装修污染等效果。
平安树浇水不当导致叶黄 浇水过多或者过少 浇水不当是导致平安树叶子发黄的一大原因，浇水过多或者过少都有可能出现叶子发黄的现象。 浇水过多会导致平安树根部积水，水分无法完全吸收，并且土壤排水不畅，导致根系受损，腐烂。其发生特点是植株老叶没有明显的变化，而幼叶发黄。 浇水少或者由于天气过于炎热，导致平安树缺水干旱，叶子发黄，其特点是自下而上叶片受损发黄，以老叶为先。 解决办法 浇水一定要合理，控制浇水量，浇水不宜过多，湿润为好，防止根部腐烂。 当遇到干旱引起的叶子发黄现象，要及时进行浇水，否则因为植株缺水的时间过长，会导致全株植物枯黄，掉落，甚至死亡。 平安树施肥不当导致叶黄 施肥过浓或者过淡 肥料是植物生长的必备元素，施肥过多或者过少，都可以引起平安树的叶子发黄。施肥过多，会使平安树幼叶肥大，叶面凹凸不平。而施肥不足或者施肥的浓度过低，导致施肥起不到作用，间隔时间过长引起的平安树叶子发黄，其特点是幼叶和嫩茎先黄。 解决办法 如果发现施肥太多了，要适当进行控肥，在保证盆土不会积水的情况下适当多浇水，使肥料能够及时排走，降低肥料浓度。而施肥量过少，就要及时进行施肥，增加肥料施放的次数，否则会造成全株黄叶或者导致植株的死亡，切忌不可大量施加浓肥。 平安树缺铁导致叶黄 缺铁表现 平安树缺铁也会导致叶子发黄。由于施肥的条件变化，导致植物黄叶现象严重，特点是幼叶较为明显，老叶较轻，叶肉变为黄色，叶脉变为绿色，并使之形成一个典型的网络。 解决办法 这种情况可以使用硫酸亚铁水溶液来解决，将饼肥，硫酸亚铁以及水分合理进行配制，并浇洒。 平安树因光照和温度原因而叶黄 光照强烈或者温度过低 在夏季光照强烈的时候，烈日的照射会导致平安树的叶子发黄。而温度过低引起的平安树叶子发黄则是由于冬季的温度较低，特别是在室外。如果气温低于5度，平安树就会被冻害，出现叶子发黄现象。 解决办法 在夏季，可以将平安树放到遮光50%左右的环境中进行养护。冬天应将平安树移至室内养护，并且保持10度以上的温度，减少浇水次数。 新盆移栽或者土壤稀少 一般，在平安树刚买回来的时候，会因为盆土的原因而呈现叶子发黄的现象。 由于平安树在买卖之前需要进行移植，新盆新环境，会使平安树出现一定程度的黄叶现象，而有卖家为了省土壤，会在盆的最下面放置一些土渣垃圾，最上面才覆盖一层土，也会导致平安树叶子发黄枯萎。 解决办法 刚买回家的平安树需要缓苗，要把它放在阴凉通风的地方养护一星期后，再逐渐见光。如果发现土壤有问题，可以将平安树脱土去盆，换上新土重新栽种。 平安树因其他原因而叶黄 病虫害 病虫害容易造成平安树的根部受损，继而导致叶子发黄。要细心检查平安树的生长状况，根据症状对症下药。有烂根情况就清除坏根，消毒后重新栽种。 通风不畅 平安树的生长环境有一定的要求，在通风的环境下生长比较好，如果生长的环境不通风，很容易造成叶子发黄。所以一定要加强室内的通风。 水质问题 在水质方面，长时间使用碱水浇平安树，会导致叶子慢慢变黄，时间长了就会脱落。因此，在浇水的时候要注意水的酸碱性，并要在平时多施腐熟的有机肥，如粪肥、泥炭、锯木屑、食用菌等，渐渐改良碱性土壤，或者直接换土。
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Miss Chen
2017年12月22日
Miss Chen

茉莉花叶色翠绿，终年不凋，夏、秋季节开花不绝，其色如玉，其香浓郁，能给人有清凉舒适的感受。茉莉花的香气素有“天下第一香”的美称，它有着玫瑰的甜郁、梅花那样清芳和兰花那样幽远，朴素自然，堪称盆花的佳品，深受人们的喜爱。茉莉花除供盆栽观赏外，也是熏制花茶的主要原料。
茉莉花浇水量导致叶子发黄 浇水过多过少都可导致茉莉花叶子发黄。浇水过多时，表现为嫩叶无光泽，老叶无太多变化，新枝逐渐萎缩，停止生长；浇水过少，会使老叶从上而下逐渐掉落，但新叶正常生长，养分供应不足，遇到以上现象，应当注意浇水量的适宜，保证盆土湿润，不可积水。 茉莉花施肥量导致叶子发黄 茉莉花的施肥也很重要，施肥过多导致新叶颜色变为褐色，老叶逐渐发黄枯落；施肥过少会使植物的根须罗作一团，得不到养分的吸收，导致叶片变黄，遇到以上情况，应当及时对茉莉花进行换盆，平时薄施勤肥，保证植物的正常养分供应。 茉莉花的土壤导致叶子发黄 土壤也是导致叶子发黄的重要因素，茉莉花的土壤应当选用酸性的土壤，如果土壤呈弱碱性，会导致叶片从黄转绿，甚至脱落，应当使用酸性的营养土进行养护。 光照和温度导致茉莉花叶子发黄 茉莉花是喜光照和温暖环境的花卉，因此要将茉莉花放置在阳光散射光照充足的地方进行养护，夏季高温炎热，不可直接暴晒在阳光下，注意室内同分及降温，盆土不能过于干燥或湿润，否则容易导致盆株叶子发黄，枯萎。 茉莉花冬季养护不当导致叶子发黄 冬季养护不当也会导致茉莉的叶子发黄，茉莉花冬季应当放置到室内进行养护，要注意室内的温度最低不可低于3℃，最好保持在10-15℃左右，叶子就会很少发黄枯萎。
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Miss Chen
2017年12月22日
Miss Chen

铜钱草又名香菇草，属多年生湿生草本作物。铜钱草叶片滚圆，生命力非常旺盛，无论是土养还是水培存活率都非常高。且铜钱草地下根茎生长迅速，每节都可新生根和叶，到夏秋天还可开出黄绿色的小花朵。铜钱草的根茎叶都可当蔬菜食用，具有清热除湿、利尿解毒的作用。
铜钱草叶子发黄症状 外围发黄 第一种情况是，铜钱草底部或者外围的叶子枯萎发黄，通常情况靠近盆土或水表面的叶片呈现黄褐色状，而外围的叶片会呈现黄黄的没有光泽。这种情况，大多是因为养护环境不理想导致的，或者是植株正常的新陈代谢。这一发黄现象对铜钱草的生长影响不大！ 全部叶子发黄 第二种情况是，铜钱草叶子全部发黄。这种情况下，叶片发黄是一种循序渐进的情况，没有规律可循。这就是一种病态的发黄，原因很多如果不及时处理，整盆会渐渐的萎蔫腐烂。 浇半截水 浇半截水指的是浇水是盆底没有水渗出，水分只滋润了茎而没有渗到根部，长期浇水不透，根部水分不足，就会出现发黄的现象。另外水培的铜钱草，若容器中水位较低，也会出现此现象。 通风差，环境湿 铜钱草的盆土长期处于潮湿或过于干燥的状态，没有做到见干即浇水，加上环境过于潮湿（虽然铜钱草是水生植株，但是土培时过于潮湿也是生长不好的。） 另外一个原因就是环境憋闷，多肉植物可以闷养，但是绿叶植物可不行。就像人在桑拿房过长的时间也会脱水，萎蔫的道理是一样的。闷闷的环境下，叶子会下垂、发黄。 急于出室 铜钱草不耐寒，入冬前要及时移到室内，若根系冻伤就会出现发黄。 过冬之后，天气转暖，但天气寒潮频繁，若急于出室，一时无法适应环境，也会出现叶子发黄的现象。 养分不够 铜钱草的养分来源有两个，一是叶片的光合作用，二是施肥。当叶片布满灰尘长期不清洗，阻碍光合作用导致养分缺失；铜钱草健壮生长需要养分均衡，当百缺少磷肥时，就会出现叶子发黄的现象。 铜钱草叶子发黄的解决方法 半水半土养殖 全土或全水养殖都会出现养分、浇水不当等问题，最好的方法是半土半水，土壤可以为根部提供充足的养分（土壤的选择没有什么讲究，普通的就可以），水培有能满足水分的需求，一举两得。但因为铜钱草繁殖较快，很快就会长满盆，记得及时清理。 阳光充足 对待这种绿叶植物，叶子黄了最佳的解决方法就是将黄叶剪掉，在保证水分和养分充足的情况下，放在阳光下多晒太阳，只要不暴晒，铜钱草会生长得很好。 分株栽种 解决铜钱草叶子发黄还有一个终极的方法，就是分株。因为铜钱草好活，而每盆铜钱草发黄的原因都不相同，不可能做到面面俱到，所以最保险的方法就是——分盆，让每一个叶片都有充足的生长空间。 全新的水、土、盆，全新的铜钱草，不久就可以养出一盆全新的铜钱草，一盆死掉还有另一盆做备份。
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Miss Chen
2017年12月22日
Miss Chen
Description: This perennial wildflower is about 1-2' tall, branching occasionally to frequently. It is ascending to erect, although some of the side branches may sprawl across the ground in open areas. The central stem and side branches are light green, hairless, and terete or angular in cross-section. The alternate compound leaves are odd-pinnate with 5-15 pairs of leaflets and a terminal leaflet; the compound leaves are up to 3" long and they have short petioles. Individual leaflets are 3/8" long and 1/8" across; they are medium green, oblong, hairless, and smooth along their margins. Each leaflet has a very shortFloral Spike petiole and a tiny pointed tip. Upper stems terminate in individual spikes of flowers that are short and cylindrical in shape; individual flowers and their bracts are densely crowded together along the length of each spike in all directions. The petals of these flowers are medium purple or rose-pink (rarely white), while their sepals and bracts are green-white. Each flower has 5 petals, 5 sepals, 5 stamens, and a pistil with a single style. The petals are oblanceolate or obovate and longer than the sepals. The short sepals are lanceolate with green tips and white bases. Underneath each flower, there is a lanceolate bract with an elongated tip that is awn-like. The exerted stamens have white or pale purple filaments and orange to brown stamens. The blooming period occurs from mid- to late summer and lasts about 1-2 months. There is no noticeable floral scent. Each flower is replaced by a short seedpod with a slender beak that is largely enclosed by the persistent sepals; each seedpod contains 1-2 smooth seeds. As the seeds mature, the floral spikes become dark brown. The root system consists of a short stout taproot with fibrous rootlets. This wildflower reproduces by reseeding itself. Individual plants typically live less than 8 years. Cultivation: The preference is full or partial sunlight (at least one-half day of sunlight), moist to slightly dry conditions, and a thin rocky soil. The pH of the soil should lie within the range 6.0–8.0; strongly acidic soil should be avoided. This wildflower will adapt to ordinary clay-loam garden soil if its location is sunny and well-drained; however, it is intolerant of competition from taller and more aggressive plants. Range & Habitat: Leafy Prairie Clover has been observed in only a few counties in northern Illinois (see Distribution Map). Today, it is restricted to 2-3 small colonies in Will County; the populations of the remaining colonies have been extirpated by development or over-collection. Leafy Prairie Clover also occurs in Tennessee and Alabama. Populations have declined in all three states. This native plant is quite rare and it is listed as 'endangered' by both the state of Illinois and the Federal government. In Illinois, habitats are restricted to mesic dolomite prairies and rocky riverbanks. In Tennessee and Alabama, habitats are restricted to cedar glades and meadows along the edges of cedar glades. Faunal Associations: Floral visitors of Leafy Prairie Clover are probably similar to the floral visitors of Dalea purpurea (Purple Prairie Clover); the insect visitors of the latter include many kinds of bees (short-tongued & long-tongued), butterflies, flies, and occasional wasps. These insects are attracted to the nectar and/or pollen of the flowers. The caterpillars of the butterfly Colias cesonia (Dogface Sulfur) feeds on the foliage of Dalea spp. (Prairie Clovers) and other species in the Bean family. Other insects that feed on Prairie Clovers include Apion amaurum (Weevil sp.), Apion capitone (Weevil sp.), and Pachybrachis othonus (Cylindrical Leaf Beetle sp.); none of these records are specific to Leafy Prairie Clover, however. The foliage of Leafy Prairie Clover is highly palatable to mammalian herbivores, including deer, rabbits, groundhogs, cattle, horses, and others. In Illinois, rabbits have been a major cause of plant mortality for this species. This rare wildflower should be protected from such animals where their populations are excessive.
Photographic Location: The wildflower garden of the webmaster in Urbana, Illinois; the photographed plant was obtained from a specialist nursery using horticultural sources, rather than wild-collected material. Comments: Unfortunately, this attractive wildflower is approaching extinction in natural areas. Compared to other Dalea spp. (Prairie Clovers), it has a more leafy appearance. Leafy Prairie Clover can be distinguished from other Prairie Clovers in Illinois by the number of leaflets per compound leaf (typically 21-25, although there can be fewer or more leaflets than this). Both Dalea purpurea (Purple Prairie Clover) and Dalea candida (White Prairie Clover) have fewer leaflets per compound leaf (less than 10). As it common name suggests, White Prairie Clover has flowers with white petals. The floral bracts of Purple Prairie Clover are shorter than those of Leafy Prairie as they lack the awn-like tips of the latter. A species that is found in neighboring states (although not Illinois), Dalea villosa (Silky Prairie Clover) has abundant leaflets, but its foliage is covered with abundant silky hairs. In contrast, Leafy Prairie Clover has hairless foliage.
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Miss Chen
2017年12月22日
Miss Chen
Description: This perennial plant is unbranched or sparsely branched in the upper half, and 1-2½' tall. The pale green central stem has light longitudinal lines. The alternate compound leaves are oddly pinnate and about 2-7" long, consisting of 3-9 pale green leaflets. Each leaflet is linear or narrowly oblanceolate, about 1" long and less than ¼" across. The margins are smooth, and the underside of each leaflet has numerous translucent dots. Both the stems and leaves are hairless. There is a short cylindrical spike of white flowers at the terminus of the central stem and each of the major side stems. This spike is about 1-3" tall and ¾" across. The small flowers form a wreath around the bottom of the spike, which moves upward as the season progresses. Each flower is about ¼" across, with 5 petals and 5 white stamens. The flowers often have a pleasant fragrance. The blooming occurs during early to mid-summer and lasts about a month. The seeds fall a short distance from the mother plant when the wind shakes the cylindrical spikes. The root system consists of a central taproot that can extend 5' into the ground. Cultivation: The preference is full sun and mesic to dry conditions. The soil can contain significant amounts of loam, clay, sand, or gravel. This plant is slow to develop, but otherwise easy. Foliar disease isn't troublesome. Drought resistance is very good. Range & Habitat: The native White Prairie Clover occurs occasionally in scattered counties of Illinois, but it is rare or absent in the SE section of the state (see Distribution Map). Habitats include mesic to dry black soil prairies, sand prairies, savannas, openings in upland forests, and limestone glades. It is rarely observed in highly disturbed areas. Recovery from occasional wildfires is good. Faunal Associations: The nectar and pollen of the flowers attract bumblebees, Halictid bees (including green metallic bees), plasterer bees (Colletes spp.), Sphecid wasps, Tiphiid wasps, Syrphid flies, thick-headed flies (Conopidae), and small butterflies. Two oligolectic plasterer bees, Colletes robertsonii and Colletes wilmattae, visit the flowers of White Prairie Clover (Robertson, 1929; Krombein et al., 1979). Other insects feed on the seeds, foliage, and other parts of this plant. They include such species as the larvae of two butterflies, Colias cesonia (Dogface Sulphur) and Hemiargus isola (Reakirt's Blue), the seed-eating larvae of two weevils, Apion amaurum and Apion capitone, and Melanoplus keeleri luridus (Keeler's Grasshopper); see Opler & Krizek (1984), Sauer (2005), and Campbell et al. (1974). This plant is palatable and high in protein, therefore it is readily consumed by mammalian herbivores of all kinds, including rabbits, groundhogs, deer, and livestock. This can cause difficulties in establishing this plant in some areas. It is possible that small rodents may carry the seeds to their dens. Because of their high mortality rate, some of the seeds will remain uneaten, and thus are dispersed by these rodents.
Photographic Location: Photographs were taken at the Lincoln Book Bindery in Urbana, Illinois. Comments: White Prairie Clover often occurs in the same habitats as Dalea purpurea (Purple Prairie Clover) – the two are often seen together, although the former begins blooming about 2 weeks earlier than the latter. However, White Prairie Clover is the less common of the two plants. The most obvious difference between them is the coloration of their flowers. In addition, White Prairie Clover tends to have more elongated flowering spikes with hair-like bracts, and its foliage is longer, sparser, with a lighter shade of green. Prior to blooming, it blends into the background of grasses and other forbs rather well, and is easy to overlook.
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Miss Chen
2017年12月22日
Miss Chen
Description: This plant is a summer annual about ½-2½' tall that is abundantly branched; robust specimens can be as wide as they are tall, resembling a tumbleweed. The stems are are erect to widely spreading, terete to angular, and pale green; young stems are covered with appressed woolly hairs, often becoming less hairy with age. Along the stems, there are alternate leaves 1-3" long and ¼-¾" across; they are pale green, narrowly ovate to oblong in shape, and shallowly lobed, coarsely toothed, or undulate along their margins. Some upper leaves may have smooth margins. When lobes are present on the leaves, they are usually triangular-shaped with pointed tips. Young leaves have appressed woolly hairs on both the upper and lower sides, although they often become less hairy with age. Leaves are either sessile or they have short pedicels up to ½" long. During the fall, the deciduous foliage of this plant becomes red or purple. The upper stems terminate in either spikes or panicles of whitish green flowers. The length of these spikes or panicles is 2-12" long; their branches are frequently curved or crooked. Sessile flowers occur individually along these branches and they are widely separated from each other. Individual flowers are about 5 mm. (1/6"), consisting of 5 green sepals that curve inward, 5 stamens, and a flattened ovary with 2-3 styles. Except for its apex, the ovary of each flower is covered by the sepals. Each sepal is lanceolate-ovate, slightly keeled in the center, and membranous along its margins. The flowers lack petals and there are no bracts. Flowers are sometimes pistillate; such flowers lack stamens. The blooming period occurs from late summer into the fall for 2-3 months. The flowers are cross-pollinated by the wind. Each flower is replaced by a single horizontal seed that is covered by the persistent sepals (except at the apex). Surrounding each group of sepals and the seed, there is a pale membranous wing (wider than 0.5 mm.) that is circular and slightly fringed along its outer margin. Individual seeds are covered with translucent membranes that are chaffy. Individual seeds are about 1.5 mm. across, circular and flattened in shape, black, and smooth. During the fall or winter, the entire plant may break off at the base, becoming a tumbleweed that is blown about by the wind. As a result, the seeds are scattered across the landscape. The root system consists of a taproot. Cultivation: The preference is full sun, mesic to dry conditions, and very sandy soil. The size of individual plants is variable.
Range & Habitat: The native Winged Pigweed is occasional in northern and west-central Illinois, otherwise it is rare or absent (see Distribution Map). Habitats include dry sand prairies, dry sandy savannas, sandy areas along major rivers, beaches and sand dunes along Lake Michigan, sandy fields, and barren areas along railroads. This plant typically occurs in sandy habitats with sparse ground vegetation and loose sand. It is a pioneer species that plays a minor role in stabilizing loose sand in wind-tossed areas. Faunal Associations: Very little is known specifically about floral-faunal relationships for this species. An unidentified scale insect (Lecanium sp.) and an aphid (Macrosiphum gei) have been observed to suck juices from the foliage. Many insects that feed on Chenopodium spp. (Lamb's Quarters) undoubtedly feed on Winged Pigweed as well. Some upland gamebirds and granivorous songbirds probably eat the seeds, while mammalian herbivores probably feed occasionally on the foliage. Because the small seeds of species in the Goosefoot family can pass through the digestive tracts of both songbirds and mammals, they may be partially distributed by these animals.
Photographic Location: A sandy beach along Lake Michigan at the Indiana Dunes State Park in NW Indiana. The photographs of the foliage were taken during late July, while the photograph of the winged seeds was taken during late September. Comments: The odd-looking Winged Pigweed is the only species in its genus. It differs from other species in the Goosefoot family (Chenopodiaceae) by the appressed woolly hairs on its foliage and the winged membrane around its dry fruit. In contrast, other species in this family have foliage that is white-mealy, glandular-pubescent, or hairless. The flowers of Winged Pigweed occur individually on the branches of an inflorescence, whereas most species in the Goosefoot family have flowers that occur in clusters.
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Miss Chen
2017年12月22日
Miss Chen
Description: This parasitic vine is a summer annual up to several feet long that branches occasionally. The stems are yellow to orange, more or less terete, glabrous, and about 1 mm. across. These stems curl around the stems of suitable host plants, climbing upward and often smothering them. Sessile suckers (haustoria) occur along these stems at frequent intervals, causing them to have a warty or bumpy appearance. These suckers extract water and nutrients from the host plants. There are no leaves and this vine does not produce chlorophyll; it is totally dependent for survival on its host plants. As the vine continues to grow, dense clusters of 5-25 flowers are occasionally produced. Each flower is about 3 mm. across, consisting of a light green to yellowish green calyx with 5 lobes, a white corolla with 5 triangular or ovate-triangular lobes with incurved tips, 5 exserted stamens, and a light green to yellowish green ovary with a pair of short styles with knobby stigmas. The glabrous calyx is short-campanulate (bell-shaped) and each lobe either overlaps adjacent lobes slightly or it is non-overlapping. The circumference of the calyx is circular (round), rather than angled. Individual calyx lobes are usually oval in shape with obtuse or rounded tips. Fertile anthers are up to 0.5 mm. in length and bright yellow, becoming light brown as they wither away. The pedicels of the flowers are light green to yellowish green, glabrous, and very short (0.5-2.0 mm. in length). These pedicels are initially terete and about 1 mm. across, but they may become swollen and angular as their flowers develop. Sometimes solitary bracts occur at the bases of flower clusters, or at the bases of individual pedicels. The blooming period occurs from mid-summer to early fall, lasting about 1 month. The flowers are either mildly fragrant or not noticeably fragrant; in the absence of cross-pollination, they are self-fertile. As the flowers continue to mature, their ovaries (developing seed capsules) swell in size, becoming 2-3.5 mm. across and subgloboid (depressed-globular) in shape. Immature seed capsules are light green, becoming yellowish orange as they begin to mature, and finally turning light brown to brown at full maturity. These capsules eventually split open irregularly to release their tiny seeds (up to 4 seeds per capsule). The seeds can spread to other areas by wind or water. Individual seeds are 1.0-1.5 mm. in length, ovoid-angular in shape, and dull yellow to brown. The seed surfaces are minutely pitted (requires 20x magnification or higher to see). While an elementary root system develops from a newly germinated seed, it soon withers away as the seedling becomes attached to a host plant.
Cultivation: This parasitic vine requires a suitable host plant in order to survive. Examples of such host plants include Baptisia australis (Blue Wild Indigo), Trifolium spp. (Clover), Medicago sativa (Alfalfa), Beta vulgaris (Sugar Beet), Solanum tuberosum (Potato), Polygonaceae (Smartweeds & Knotweeds), Allium cepa (Onion), and many others. Unsuitable host plants include Glycine max (Soybean), Equisteum arvense (Field Horsetail), and most grasses and sedges. Field Dodder occurs in drier habitats than many other Cuscuta spp. (Dodder species). It is typically found in either sandy or non-sandy areas where there is full sun or partial sun. The seeds can persist in the soil and remain viable for several years. Range & Habitat: Field Dodder (Cuscuta campestris) is occasional throughout Illinois (see Distribution Map), where it is native. Field Dodder is one of the more common Dodder species in Illinois and it is widely distributed in North America. Habitats include banks of rivers, fields, croplands, neglected flower gardens, and waste areas. This dodder is considered a significant pest of several field crops. It is found primarily in disturbed areas.
Faunal Associations: Robertson (1929) observed small bees sucking nectar from the flowers of Cuscuta spp. (Dodder species), including Halictid bees (Lasioglossum) and plasterer bees (Colletes). Such floral visitors appear to be uncommon. Various aphids are able to suck juices from dodder vines and successfully reproduce, weakening them substantially (Harvey, 1966). Aphids that have adapted particularly well to these parasitic vines include Aphis craccivora (Cowpea Aphid), Macrosiphum euphorbiae (Potato Aphid), and Myzus persicae (Green Peach Aphid). Mammalian herbivores seem to avoid plants that are badly infested with dodder. These parasitic vines may be toxic to such animals if they are eaten in sufficient quantity. Nonetheless, should such animals consume these parasitic vines with their host plants, the seeds of dodder can pass through their digestive tracts and remain viable for several years. Because the tiny seeds of these vines become sticky when they are wet, they are probably spread to other areas by the feet or fur of mammals, the feet or feathers of birds, and the shoes of people. Agricultural machines may spread this vine into different fields through the use of contaminated crop-seed. Some materials that are used in gardens (e.g., contaminated mulch & soil) may also facilitate its spread.
Photographic Location: A flower garden at a city park in Champaign, Illinois, where this dodder infested Baptisia australis (Blue Wild Indigo). Comments: Field Dodder (Cuscuta campestris) can be distinguished from some Dodder species (Cuscuta spp.) in Illinois by the 5-lobed corollas of its flowers: the lobes of these corollas have very acute tips that are incurved. A similar species, Common Dodder (Cuscuta gronovii), also has 5-lobed corollas, but the tips of its lobes are more blunt and they are less incurved. Field Dodder is also similar to Prairie Dodder (Cuscuta pentagona). This latter species has more angular calyces, while its seed capsules are slightly smaller in size and less depressed in shape. Prairie Dodder also has shorter anthers and shorter seeds. In the past, Field Dodder was considered a variety of Prairie Dodder (Cuscuta pentagona calycina), but they are now regarded as distinct (Costea et al., 2006; Costea et al., 2015). Other common names of Cuscuta campestris include Large-seeded Alfalfa Dodder and Golden Dodder, while another scientific synonym of this species is Cuscuta arvensis.
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Miss Chen
2017年12月22日
Miss Chen
Description: This plant is a summer annual up to 2' tall and 3' across. Robust specimens branch frequently and have a bushy appearance with a flattened top, while dwarf specimens on sterile ground branch relatively little; the latter can be less than 6" tall. The stems are covered with appressed hairs that shortly turn brown; the lower stem on robust specimens becomes rather stout. The leaves are usually alternate, although the uppermost leaves are often opposite. They are up to 2" long and ¾" across, broadly lanceolate-oblong, and smooth along the margins. The upper surface of each leaf is green and finely pubescent, while the lower surface is whitish green and woolly from appressed hairs. Many of these hairs are stellate (branched and star-like). The petiole of each leaf is about ½" in length. The foliage exudes a fetid aroma from glandular secretions; the leaves and stems have a clear sap. Prairie Tea is monoecious. The small male flowers occur in erect clusters from the axils of the upper leaves. Each male flower has a woolly green calyx with 5 lobes that are spreading and oblong, 3-8 narrow white petals, and 3-8 white stamens. Only a single female flower develops from each axil of the upper leaves. Each female flower has a woolly green calyx with 5 lobes that are spreading and oblong, a woolly green pistil that is ovoid in shape, a pair of cleft styles at its apex, and no petals. The blooming period occurs from mid-summer to early fall and lasts about 1-2 months. The female flowers are initially erect, but later droop downward as the seed capsules develop. Each ovoid seed capsule is up to ¼" long and contains a single seed that is rather large and finely pitted (less often, 2 seeds are produced). This plant spreads by reseeding itself. Cultivation: The preference is full sun, dry conditions, and poor soil containing rocky or gravelly material. The pH of the soil can be acid or alkaline. This plant is quite drought resistant, although some of the lower leaves may turn yellow and wither away. In more fertile soil, robust specimens are produced that are bushy and attractive. Range & Habitat: The native Prairie Tea occurs occasionally in the southern half of Illinois (especially in the SW), but it is uncommon or absent elsewhere in the state (see Distribution Map). In the northern half of Illinois, this species is probably adventive from the south, otherwise it is native. Habitats include hill prairies, sandstone and limestone glades, thinly wooded bluffs, fallow fields, and gravelly areas along railroads. This species occurs in disturbed areas and higher quality habitats that are sunny and dry. Faunal Associations: Little information is available about the insects that pollinate the flowers, but they are probably small bees, flies, and/or wasps. The caterpillars of Anaea andria (Goatweed Butterfly) feed on the foliage of Prairie Tea and other Croton spp. The large oily seeds of Croton spp. are attractive to many upland gamebirds and some songbirds, including the Mourning Dove, Wild Turkey, Prairie Chicken, Bobwhite, Cowbird, and various sparrows. The fetid foliage is unattractive as a source of food for mammalian herbivores, although goats will eat it. Sometimes, Croton spp. are referred to as 'Goatweed' or 'Doveweed' because of their value as a food source to these animals.
Photographic Location: Along an abandoned railroad in Vermilion County, Illinois. Comments: The foliage of Prairie Tea is reasonably attractive, while the flowers are insignificant. The common name refers to the resemblance of robust specimens to cultivated tea plants; however, the foliage is unsuitable as a source of tea. Generally, Croton spp. are typical prairie plants of the southern plains; they are less typical of eastern tallgrass prairies, where they are often displaced by taller vegetation in fertile areas. Prairie Tea differs from other Croton spp. by the following characteristics: 1) Its leaves lack teeth, 2) each seed capsule contains only a single seed (or at most two), rather than three, 3) the female flowers are produced individually from the leaf axils, rather than in groups, and 4) the seed capsules do not exceed ¼" in length.
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Miss Chen
2017年12月21日
Miss Chen

兰花又名中国兰花、地生兰、兰草，为兰科兰属多年生宿根草本花卉。原产我国其中云、贵、川、藏分布较广，是我国传统名贵花卉，也是世界名花。 人们历来把兰花看作是高贵、典雅的的象征，并与梅、兰、竹、菊合称“四君子”。兰以清香淡雅与菊、水仙、菖蒲并称“花草四雅”，而兰花居四雅之首。兰花朴实无华，叶色常绿，叶质柔中有刚，花幽香清远，有极高的观赏价值，是陈列客厅、居室或点缀书房、门厅之珍品。
浇水不当引起兰花叶黄 叶黄原因 兰花喜欢湿润的生长环境，对空气湿度的要求比较高。浇水不足造成根系受损或者是空气过于干燥的时候，就会导致兰花叶子发黄。反之，如果浇水过多，盆内积水并且排水不畅，就会使兰花的根部缺氧腐烂，会出现黄叶，甚至死亡。 解决办法 浇水要掌握技巧，要根据盆土的干燥情况来进行浇水，适量适时浇水。避免盆土过干或者过湿。注意兰花生长环境的空气湿度，如果空气过于干燥，就要经常喷水，保持湿度。 施肥不当引起兰花叶黄 叶黄原因 如果是施肥引起的兰花叶黄，一般是因为一次性施肥过多，导致兰花的根茎灼伤而叶黄。因为兰花的生长其实不需要大肥，施肥便要薄施勤肥。 解决办法 兰花在施肥方面，需要薄肥巧施，切忌施浓肥、大肥以及未腐熟的液肥。在施肥后的第二天，要浇一次清水，使肥料得到稀释，避免肥害的发生。 光照引起兰花叶黄 叶黄原因 兰花对光照的要求比较严，它喜欢较阴的生长环境，比较畏阳但又不能缺少阳光。因此光照不足或光照过强，兰花的生长都会受到影响。光照强，容易发生日灼，使兰花的叶片受伤而发黄；光照弱，兰花的植株养分不够，容易叶片发黄。 解决办法 兰花喜欢半阴，早春和冬季可全日照养护外，其他时间将植株的放在通风良好的地方，避免阳光直晒。 病虫害引起兰花叶黄 叶黄原因 如果兰花遭遇病虫害，也会出现叶子发黄的现象，如叶斑病、炭疽病等，烂根也会导致叶子发黄，甚至危害更重。 解决办法 一般兰花出现了病虫害，影响到叶子会是一个渐进的过程。在病虫害发病初期，如果能及时发现，就能做出应对措施。根据兰花出现的症状，来判断兰花是遭遇了那种病虫害，并选择相对应的治疗措施，喷洒农药或者人工防治，会缓解兰花叶子发黄的情况。 新陈代谢引起兰花叶黄 叶黄原因 兰花的生长需要随着植株的生长而进行新老更替。因为发展新叶的需要，老叶子便不会继续生长，而是变黄枯萎并脱落。 解决办法 因为新陈代谢导致的叶子发黄，是正常的现象，无需过多担心。
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Miss Chen
2017年12月21日
Miss Chen

常春藤是一种颇为流行的室内大型盆栽花木，尤其在较宽阔的客厅、书房、起居室内摆放，格调高雅、质朴，并具有南国情调。是一种株形优美、规整、世界著名的新一代室内观叶植物。可以净化室内空气、吸收由家具及装修散发出的苯、甲醛等有害气体，为人体健康带来极大的好处。原产欧洲、亚洲和北非。它对环境的适应性很强。喜欢比较冷凉的气候，耐寒力较强，可入药。
常春藤叶子发黄原因 光线的影响 常春藤是冬季常见的绿叶植物，冬季不需要遮阴，光线适当强一点也无所谓。但夏季阳光强烈，若不移动，还是正常的接受阳光照射，容易造成叶面出现坏死的情况。 温度的影响 常春藤喜欢凉爽的环境，怕闷热、霜冻，尤其是秋冬的早霜，若没有及时移到室内，叶片遭受霜冻耷拉，变黄。还有就是夏季室内养殖，不及时通风，环境闷热，也会造成黄叶。 水分的影响 常春藤最大的观赏之处在于叶片，而水分的供应是保证叶片饱满的前提。生长期间需要保证盆土湿润，但不能积水，许多花友在养护过程中把握不好度，导致盆土忽干忽湿，植株得不到充足的水分，植株代谢缓慢，导致植株黄叶。 病虫害 病虫害是植株养护过程中无法避免的，但在某些情况下人的肉眼是看不到叶片上有虫子的，防治不及时，就会造成植株黄叶。或者在叶斑病的作用下，植株不会有任何征兆的黄叶，防不胜防。 缺肥 常春藤叶总发黄还可能是饿的，人饿了会吃饭，植物饿了需要养分。当植株叶子发黄，很显然是缺铁，是在养护过程中，长时间未施肥，或施肥时各元素不均衡。 常春藤叶子发黄怎么办 温度要适宜 既然常春藤对温度比较挑剔，那就满足它，毕竟你也觊觎人家的美色。控制环境温度在20~25℃，并且要时刻关注环境湿度，经常通风。冬季温度要控制在5℃以上，10℃左右最好。 光照度要适度 适宜的光照下，常春藤的叶片会叶形一致，叶色鲜明。若植株因光照原因变黄，严重的叶片直接剪掉，保留刚长出的嫩叶，给予适当的光照，使其慢慢恢复。 浇水要适量 在生长的季节要见干湿（即是不能让盆土过湿，也不能过干），如果水分过多便会已发烂根落叶。尤其是在冬季的温度是偏低的，所以尤其要控制浇水，只要保持盆土有点湿润便可。 施肥要合理 在家庭培养常春藤时，盆土可选用腐烂叶或者是炭土加1/4河沙和少量骨粉混合而配成的土壤，生长季节2至3周可施1次稀薄饼肥水。一般夏季和冬季不要施肥，施肥时也要注意不要选择偏偏施氮肥。在施肥时也要注意不要玷污叶片，以免引起叶片枯焦。因缺铁造成黄叶的要及时补充铁元素，浇灌硫酸亚铁溶液。
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