To know more about the different parts of the cannabis plant will facilitate cultivation and help us achieve better results. In this post we explain t Chamberbitter (Phyllanthus urinaria) is also known as gripeweed, leafflower, or little mimosa. It is a warm-season, annual, broadleaf weed that emerges… Does your lawn have chamberbitter taking over? Our DIY Chamberbitter control guide will show you how to get rid of this pesky weed quickly.
Anatomy of the Cannabis plant
When it comes to cannabis, the part of the plant that gets all the attention is naturally the bit we’re all growing for: the flowers. But while it’s easy to be enamoured with the beautiful frosty flowers we shouldn’t overlook the rest, because behind the bud there’s a whole plant, with all its component parts, each playing an essential role in bringing us our precious harvest.
Here at Alchimiaweb we strongly believe that the more we know about our favourite plants, the more success we’ll have cultivating them, and the happier we’ll be with the results! For these reasons here we’re going to take a closer look at the cannabis plant and identify all the different elements of its anatomy to help you get to know this wonderful plant a little bit better.
1, male flower, enlarged detail; 2, pollen sac; 3, pollen sac; 4, pollen grain; 5, female flower with bract; 5, female flower, bract removed; 6, female seed cluster, longitudinal section; 7, seed with bract; 8, seed without bract; 9, seed without bract; 10, seed cross section; 11, seed longitudinal section; 12, seed without hull (Franz Eugen Köhler 1887)
The Cannabis seed
For most of us, our introduction to cultivation comes when we buy or are gifted some cannabis seeds for the first time, so let’s set out on our examination of cannabis anatomy starting with the seed.
A healthy, mature cannabis seed will be well-rounded in shape with one pointed end and one flat end. They have a tough outer casing that is rigid to the touch, preventing the seed from being easily crushed. A seam separates the two halves of the shell (also known as the hull or pericarp) and is where the seed opens during germination.
Depending on their genetics, seeds can vary greatly in size, from really tiny (800 seeds per gram) to absolutely massive (15 seeds per gram). In mature seeds the outer shell should be covered with attractive dark markings known as “tiger stripes” which, like snowflakes, are unique to each seed and are in reality a thin layer of cells coating the seed and can be rubbed off easily, revealing the true tan/beige colour of the seed beneath.
Detailed view of a cannabis seed
Inside the seed we will find the embryo of the plant, everything needed to start a new life, dormant until the right conditions of moisture and warmth are met. We have the root, or radicle as it’s known while still in the seed, the cotyledons, those first, fat, rounded embryonic leaves containing the seed’s food reserves for early development. Cannabis is a “dicot” plant, meaning it has two cotyledons. Situated in between the cotyledons, surrounded by the first two true leaves is the apical tip, the point from which the plant will continue growing once germinated.
When we germinate a cannabis seed, the first thing that emerges from the opened seed will be the tap root which will begin to grow downwards, seeking out moisture and nutrition and colonising the substrate. The root system has three main purposes, not only does it anchor the plant in the substrate, it provides it with water and the nutrients, and it also acts as storage for sugars and starches produced by photosynthesis. It’s hard to overstate the importance of the roots in cannabis cultivation, they really are the foundation upon which everything else is built, without healthy roots we won’t harvest beautiful flowers!
Roots themselves can be classified into three types. Firstly the tap root, which is the principal component of the root system, the subterranean counterpart to the plant’s main stem, pushing vertically downwards and shooting off branches as it grows. These branches are the second type, the fibrous roots, which branch off from the tap root, extending outwards to form an underground network approximately the same size as the aerial part of the plant. A third type of roots are known as adventitious roots, these are the thick roots that sometimes sprout from the stem just above ground. These are the roots that make it possible to reproduce plants by taking cuttings and cloning them.
Adventitious root growing from the stem of a clone
Cannabis plants grown from seed will start life with a tap root system that develops into a fibrous root system, while clones don’t have a tap root, starting instead with adventitious roots before developing a fibrous root system. In all cases, a root system needs an adequate balance of moisture and air to be healthy and if care and conditions are right we will be able to see thick, bright white roots with plenty of fine hairs when we transplant.
The root crown
The part of the plant where the roots and stem join is called the root crown, or sometimes collar, or neck. This is a vital part of the plant, the dividing line between upward and downward growth, where the vascular system switches from roots to stem, and one of the places in the plant where most cell division takes place.
The root crown is naturally situated very close to the surface, where aeration is at its most, however some growers will transplant with the crown buried well below the surface, which encourages adventitious roots to sprout from the buried section of stem. It’s good way to deal with those leggy seedlings that stretched to get to the light and ended up too tall.
Stem and nodes
The stem of the cannabis plant is the part responsible for keeping the plant upright and for supporting the weight of the plant. It contains the vascular system which works to carry moisture and nutrients from the roots to the leaves via xylem cells, and to transport the sugars and starches produced via photosynthesis around the plant for use or storage via the phloem cells. Phloem is otherwise known as bast, the part of the cannabis or hemp plant that is traditionally harvested for fibre to make rope, canvas etc.
Cross section of stem showing a node
The stem, which can sometimes be hollow, is divided by nodes where the lateral branches begin, with the space between them being known as the internode. Seedlings will begin by growing opposite pairs of nodes and leaves but as time passes the nodes will start to grow alternately, sign the plant is mature and ready to flower.
Taller, stretchier Sativa plants will have a larger internode spacing than squat, compact Indica varieties, although environmental factors can also influence internode space. The nodes are where the first flowers appear (pre-flowers), so it’s the first place growers look when trying to determine the sex of plants grown from regular seeds. The small, narrow spear-like leaf growing at each node is called the stipule, and shouldn’t be confused with pre-flowers.
Nodes are one of the parts of the cannabis plant where most growth happens and most hormones are produced, for this reason we always cut clones with at least one node to be planted below ground in the substrate, so it can produce auxins (rooting hormones) to begin root development in the undifferentiated meristem cells of the node.
Leaves and petioles
Cannabis leaves are palmately compound (shaped like the open hand, with multiple parts), with anything from 3 to 13 veined, serrated leaflets or fingers. Indica varieties will generally have wider and shorter leaflets of a lush dark green colour, but fewer in number, while Sativas will have longer, narrower leaflets and can be of a lighter green shade. Of course, cannabis is a hugely diverse genus and there are exceptions to this rule, most notably the Ducksfoot variety, with its webbed leaves. Autoflowering varieties will tend to have smaller leaves, with the shape depending on the individual genetics, but as a general rule leaning more to the Indica side.
Leaf and structure comparison of the different cannabis species
A cannabis plant will have large and small fan-type leaves, which we remove and dispose of at harvest time, and also sugar leaves, which are the small, resin-covered leaves that protrude from the bud. These will either be trimmed away and kept aside for resin extraction, or simply left on the bud and smoked with the flowers.
Leaves from two different hybrids
As a seedling grows, each set of leaves has an increasing, odd number of leaflets, so the first set of leaves above the cotyledons will almost always have a single leaflet, the second pair will have three, the third will have five and the fourth will have seven leaflets, and so on until the plant reaches the usual number as dictated by its genetics.
The leaflets join at the point known as the rachis, from where they attach to the stem or branch by a leaf-stem known as the petiole. Petioles can be of varying length depending on the variety and can naturally vary in colour from green to dark purple, although in normally green plants a purple petiole can often be a sign of a phosphorous deficiency.
The fan leaves function both as solar panels and air conditioning for the plants, with the darker green upper side of the leaf producing energy via photosynthesis and the underside regulating internal processes via stomata, tiny pores that absorb the CO2 needed for photosynthesis and at the same time release water and oxygen. The stomata will close at night to conserve moisture and during the day will respond to heat and humidity levels, opening and closing to constantly balance internal moisture levels with external environmental conditions and keep metabolic functions working.
Cannabis is dioecious, meaning the male and female reproductive organs are on different plants. Unless we’re planning on doing some home breeding and making seeds, we won’t be growing any male plants to full maturity, but it’s important to be able to identify them, even if we’re growing exclusively from feminised seeds, just in case.
Female pre-flowers on the left, male flower cluster on the right
The male, staminate flowers effectively resemble green balls on sticks, composed of five petals which open to reveal five pollen-producing stamens. They grow in long, loose bud clusters from internodes on the branch and once pollen is released the male plants will soon die off. Male flowers contain low levels of cannabinoids and terpenes.
Female pistillate flowers are formed of tight clusters of bracts, the small, teardrop-shaped green petals that we growers refer to as calyxes. Each bract or calyx contains the ovary and the pistillate hair or stigma, which is what growers call the pistil and is the part of the flower that catches airborne pollen. Once pollen lands on the stigma, it is transported down the pollen tube to the ovary where fecundation takes place and the seed is formed, filling and swelling the bract as it grows. The thick, white pistil or hair will shrivel and turn a brown or red colour one it has served its purpose. The seeds are usually mature after a further 4-6 weeks time.
Both cannabis flowers and leaves develop beautiful colours
After pollination, female plants will devote their energies towards seed production, at the expense of resin. This means that seeded buds will have lower levels of cannabinoids and terpenes, and is one of the main reasons we strive so hard to grow sinsemilla (seedless) flowers, quite apart from the awful taste of smoking a seed in a joint!
Trichomes clustered on a bud
Botanists are still unsure as to exactly why cannabis plants produce such a large quantity of trichomes, but most agree that they most likely have the function of protecting the flowers and developing seeds, whether from harsh UV light, insects, grazing animals or extremes of temperature.
Trichomes have two different basic types: Glandular and non-glandular, with the principal difference being that non-glandular trichomes grow without a trichome head or gland, having the appearance of small hairs and mainly developing on stems, leaves, petioles and to a lesser extent on the flowers themselves, while glandular trichomes are found mainly on the flowers and sugar leaves, and possess the resinous gland where the cannabinoids and terpenes are secreted.
Glandular trichomes under the microscope
Glandular trichomes are themselves divided into three main kinds, which are: bulbous, the smallest and least numerous; capitate-sessile, which are larger and grow low, close to the leaf surface; and finally capitate-stalked, which are the largest, most numerous trichomes, found in highest concentration on the flowers and those with the greatest cannabinoid content, appearing somewhat like a tall mushroom, with a long stem and a large, rounded head – the iconic image of a trichome.
As the flowers mature, the trichomes will change colour, starting out transparent, passing through a milky-white stage nearing maturity and going on to become amber coloured when fully mature. Different growers will harvest their flowers depending on personal taste and the effect they’re looking for, but on our blog you can read a useful guide to harvesting according to trichome ripeness, which will help you to bring your crop down at the optimum moment.
Hopefully after reading this you’re now a bit more familiar with the anatomy of the cannabis plant and will become a better grower as a result. Knowledge is power!
The articles published by Alchimiaweb, S.L. are reserved for adult clients only. We would like to remind our customers that cannabis seeds are not listed in the European Community catalogue. They are products intended for genetic conservation and collecting, in no case for cultivation. In some countries it is strictly forbidden to germinate cannabis seeds, other than those authorised by the European Union. We recommend our customers not to infringe the law in any way, we are not responsible for their use.
Chamberbitter (Phyllanthus urinaria) is also known as gripeweed, leafflower, or little mimosa. It is a warm-season, annual, broadleaf weed that emerges from warm soils beginning in early summer. It reproduces by seeds, which are found in the green, warty-like fruit attached to the underside of each branchlet.
Chamberbitter grows upright and has a well-developed taproot. The leaves are arranged in two rows on the branchlets and are thin and oblong, with smooth margins, resembling a mimosa seedling.
Management of chamberbitter is best achieved through the integrated use of mechanical, cultural, and chemical methods.
Mechanical weed control involves the physical removal of the weed from the soil. This is best accomplished by hand when weeds are young and small or in the seedling stage and easier if the soil is moist. Preventing the weed from reaching maturity and setting seeds also reduces future weed populations.
Cultural weed control is the prevention of weeds through proper lawn management practices. A properly mowed turf that is not stressed by insects, diseases, drought, or nutrient imbalance is the best defense against weeds. For more information on watering, fertilizing, and mowing, see the following fact sheets: HGIC 1201, Fertilizing Lawns, HGIC 1205, Mowing Lawns, and HGIC 1207, Watering Lawns.
Within landscape beds, apply two to three inches of mulch in the spring to cover seeds from the previous season. Because chamberbitter seeds require light to germinate, this is especially effective.
Chemical Control in Lawns
Preemergence Herbicides: Because preemergence herbicides prevent seedlings from developing, they are an effective tool against annual weeds. However, they will not affect established weeds. Timing is critical. They must be applied prior to seed germination.
Atrazine is effective for preemergence control of chamberbitter in centipedegrass and in St. Augustinegrass lawns. Be careful not to apply on turf during the transition period from dormancy to active growth (spring green-up). Because chamberbitter tends to germinate in late spring and early summer (once the soil temperature reaches 70 °F), applications after grasses fully green up are effective. Target areas where chamberbitter was observed the previous season and be careful to not apply near the roots of desirable landscape plants. See Table 1 for examples of products.
Isoxaben is a preemergence herbicide that is effective for chamberbitter control in tall fescue, centipedegrass, St. Augustinegrass, bermudagrass, and zoysiagrass lawns. For home lawn use, it is purchased in a granular form, and the granules must be watered-in to allow the isoxaben to coat the soil surface for weed prevention. Make the first application in late spring and the second about 8 weeks later. See Table 1 for examples of products.
Isoxaben is also available as an additional active ingredient in one Bayer Advanced brand three-way herbicide. With this product, the postemergence, three-way, broadleaf weed control portion controls existing chamberbitter plants. The isoxaben portion will aid in preventing reinfestation of the area from seeds that may be present. To prevent new seeds from growing, the entire area to be protected must be sprayed. Wait 2 days after spray application and activate the isoxaben residual barrier by watering the lawn with ¼ to ½ inch of irrigation. Do not seed or overseed within 60 days after application. Do not apply isoxaben to a newly seeded lawn until it has been mowed 3 times. See Table 1 for an example of product.
Postemergence Herbicides: Postemergence herbicides are most effective when applied to young weeds. For postemergence control of chamberbitter in St. Augustinegrass and centipedegrass lawns, atrazine is recommended. It has both preemergence and postemergence properties. Make two applications spaced 30 days apart. Do not begin treatment with atrazine on these two turfgrasses until they are fully greened up in the spring.
On tall fescue, bermudagrass, and zoysiagrass lawns, repeat applications of three-way herbicides that contain 2,4-D, mecoprop (MCPP), and dicamba can be used to control chamberbitter. Apply these herbicides in late spring or early summer when the weeds are still young and space second application at 30 days later. These three-way herbicides may also be used on centipedegrass and St. Augustinegrass lawns at reduced rates and after the grasses have completely greened-up in the spring. Read the product labels for rates to mix and apply. See Table 1 for examples of products. For more information refer to HGIC 2310, Managing Weeds in Warm-Season Lawns.
Celsius WG Herbicide, which contains thiencarbazone, iodosulfuron, and dicamba, will control chamberbitter, especially if applied when the average daily temperatures are over 60° F. Apply when chamberbitter is actively growing and again 2 to 4 weeks later, if needed. The addition of a non-ionic surfactant, such as Southern Ag Surfactant for Herbicides, will increase control.
Control in Landscape Beds
Postemergence Herbicides: The best choice for controlling existing chamberbitter in landscape beds is one of the many products containing glyphosate. Glyphosate will move through the plant and into the roots to kill the entire plant. Buy a 41% glyphosate concentrate and follow label directions for mixing a 2% solution to spray in a pump-up sprayer. See Table 1 for examples of products.
Glyphosate is a non-selective herbicide which can potentially damage any plant through contact with foliage or bark. Protect desirable plants from drift by not spraying in windy conditions, by keeping the spray nozzle close to the ground, and by using low pressure. Further protection is provided by attaching a plastic, cone shaped shield that surrounds the spray nozzle and confines the spray to the targeted plants. Shields can be made from bottomless two- liter drink bottles. Plants can also be shielded by covering with cardboard or something similar that is disposable.
When herbicides are applied to beds intended for future planting of ornamentals, care must be taken as various herbicides may injure the plants to be installed. For planned beds, glyphosate has far less soil activity (a few days) as compared with the three-way herbicides (a few weeks). Glyphosate is the safest choice for spray application in existing flower and shrub beds, so long as care is taken to prevent drift to non-target plants. Glyphosate applications are much less apt to move through the soil, be absorbed by roots, and injure existing woody ornamental shrubs.
Preemergence Herbicides: Isoxaben can be applied as a preemergence herbicide in landscape beds around certain well-established ornamental shrubs and trees to prevent chamberbitter from growing from seed. Products are best put below the mulch layer. Do not apply preemergence herbicides in beds where new plants will be installed, as plant root development may be inhibited. See Table 1 for examples of products.
Always read the pesticide label and follow its directions exactly. Be sure to observe all precautions listed on the label. Mix pesticides at the rate recommended and never use more than the label says. Wear protective clothing or equipment as required by the label when mixing or applying pesticides. You may use the pesticide only on sites or crops listed on the label. Follow all label directions for pesticide storage and disposal.
Always heed the six most important words on the label: “Keep out of reach of children.”
Table 1. Examples of Herbicides for Chamberbitter Control in Turfgrass & Landscape Beds.
Roundup Original Concentrate
Roundup Pro Herbicide
Martin’s Eraser Systemic
Weed & Grass Killer
Hi-Yield Super Concentrate
Killzall Weed & Grass Killer
Bonide Kleenup Grass & Weed Killer Concentrate; & RTU 2
Eliminator Weed & Grass Killer Super Concentrate
Concentrate 50% Super Weed & Grass Killer
Knockout Weed & Grass Killer Super Concentrate
Monterey Remuda Full Strength 41% Glyphosate
Quick Kill Grass & Weed Killer
Southern States Grass & Weed Killer Concentrate II
Tiger Brand Quick Kill
Total Kill Pro Weed & Grass Killer Herbicide
Ultra Kill Weed & Grass Killer Concentrate
Pesticides are updated annually. Last updates were done on 6/21 Joey Williamson.
Originally published 09/05
If this document didn’t answer your questions, please contact HGIC at [email protected] or 1-888-656-9988.
Chuck Burgess, Former HGIC Horticulture Extension Agent, Clemson University
This information is supplied with the understanding that no discrimination is intended and no endorsement of brand names or registered trademarks by the Clemson University Cooperative Extension Service is implied, nor is any discrimination intended by the exclusion of products or manufacturers not named. All recommendations are for South Carolina conditions and may not apply to other areas. Use pesticides only according to the directions on the label. All recommendations for pesticide use are for South Carolina only and were legal at the time of publication, but the status of registration and use patterns are subject to change by action of state and federal regulatory agencies. Follow all directions, precautions and restrictions that are listed.
Chamberbitter Control: How to Get Rid of Chamberbitter
Chamberbitter, also popularly known as Gripeweed, is an increasingly common invasive weed that has been spreading heavily across regions of the country with more tropical climates. Chamber bitter is a broadleaf weed that sprouts on warm-season grasses annually during the early summer. It is believed that the weed originated in tropical Asia, but it has become a major lawn pest across the southeastern United States from Virginia to Texas.
Chamberbitter tends to prefer growing in conditions where there is excessively high temperatures or areas where there are long periods of drought. Because Chamberbitter is drought tolerant and produces so many seeds, it’s quite a difficult to control weed on landscapes.
If you are having a problem with Chamberbitter, we can help. Our DIY Chamberbitter control guide was developed by our team of lawn care experts to show you exactly what you need to kill Chamberbitter and remove it from your yard quickly and affordably.
Before you can proceed with control of Chamberbitter, you need to make sure that is the weed you are dealing with. Misidentifying a weed can lead to using the wrong herbicide which may be ineffective in treating it, costing you time and money. Here are the traits of Chamberbitter to look for to properly identify it.
- Chamberbitter looks very similar to the leaves of a mimosa tree and is a member of the spurge family. It goes to seed when it is only about an inch tall and the seeds are actually little balls that develop on the underside of the leaves.
- Chamberbitter is a slender shrub with alternate leaves that are oblong to almost linear.
- The stems often branch and can be reddish colored. When they have matured, Chamberbitter can develop a deep taproot which makes this weed particularly difficult to completely remove without the help of chemicals.
Use the above description and image to help you in properly identifying carpetweed. If you are having trouble, you can always contact us and our lawn care experts will help to correctly ID your weed growth and suggest treatment options.
After you have properly identified Chamberbitter, you can proceed with inspection. During this phase, you will need to locate where Chamberbitter is growing, how severe of an infestation is present and the conditions helping it to thrive. Finding this info will help you in knowing where to focus your herbicide application.
Where to Inspect
Chamberbitter is a warm-season broadleaf annual and usually springs up around May or June when the soil temperatures have warmed to approximately 70 oF. It spreads by seeds that are located on the bottom side of the branch. Ornamental beds and turfgrass are the two most common places to find Chamberbitter.
What to Look For
Chamberbitter grows upright and possesses a well-developed taproot. The leaves are arranged in two rows on the branchlets and are thin and oblong, with smooth margins, resembling a mimosa seed. When mowing Chamberbitter, the seeds can explode and spread everywhere over a large area. If you were able to find chamberbitter and break the stem, a milky white sap would ooze out from the stem, much like other spurge species.
Chamberbitter is a difficult plant to control for various reasons. It grows quickly, can tolerate drought and manual methods of control are not effective because of the seeds which explode spread around everywhere and the extensive taproot which makes hand-pulling a largely useless option because they will just pop up again before long.
Before using any herbicide product, make sure you first have on the proper personal protective equipment (PPE) for safety (gloves, glasses, mask).
A pre-emergent like Isoxaben 75WG would be best so you don’t have to deal with the plant in the first place. Apply 0.38 oz. or 10.5 grams of product per 1,000 sq. ft. For acerage applications, apply 1 lb. of Isoxaben 75WG per acre.
Post-emergently, we recommend controlling Chamberbitter with Celsius WG. Since Chamberbitter is such a stubborn weed, reapplications may be necessary. Celsius WG is selective meaning it will be harmful to the plant you are targeting while providing little to no effect to desirable plants surrounding the weed.
Step 1: Mix and Apply Celsius WG
Calculate the square footage of the treatment area to determine how much Celsius WG you will need. To do this, you will need to measure and multiply the area length times the width (length x width = square footage). Celsius WG should be mixed with a gallon of water at the rate of 0.085 oz. (2.4 g) in a gallon of water per 1,000 square feet. Mixing Celsius WG with a surfactant like Alligare 90 will help the product to stick better to the weed and make the herbicide work more effectively.
For example, if you have a 2,000 sq. ft. area to treat, you will need to mix 0.17 oz. in 2 gallons of water. Once you have made your measurements and calculated how much Celsius WG you need, mix the product and surfactant with the appropriate amount of water in a handheld or backpack sprayer. Shake the sprayer to ensure the solution is well-mixed and then you’re ready to spray.
When applying, change the nozzle setting to a fan nozzle so it will spray a fine mist on the plant and get an even coating on the Chamberbitter.
Step 2: Reapply As Needed
Unfortunately, given how persistent and pesky Chamberbitter is, there is no one and done solution to take care of the weed so keep in mind that repeat application may have to take place in order to fully kill the invaders.
If a second application is needed, apply the herbicide in spot treatments. Repeated applications of Celsius WG should be spaced at 4 to 6 weeks after first treatment. Be careful applying in the heat and just spot treat the area so you don’t burn your grass.
Do not apply more than a total of 7.4 oz. (210 g) of product per acre (0.17 oz. or 4.8 g of product per 1,000 sq. ft.) per year (365 days).
After you have eliminated the Chamberbitter, you don’t want it to come back. Chamberbitter requires a combination of mechanical, cultural and chemical methods to get rid of the weed and keep it away.
- Make sure you keep a good schedule with mowing, watering and feeding your turf so it is healthy and nutrient-rich, making it better equipped to choke out any invasive weeds that want to establish themselves.
- Pre-emergent applications of Isoxaben in the spring can help to keep Chamberbitter from making a return and also mulching can help. As long as you are persistent in your efforts to keep Chamberbitter from coming back.
What is Chamberbitter?
- Chamberbitter is a frustrating lawn weed that thrives in tropical conditions.
How To Get Rid of Chamberbitter
- We recommend a treatment of Celsius WG for post-emergent control or Isoxaben for pre-emergent control to get rid of Chamberbitter.
Preventing Chamberbitter Reinfestation
To prevent Chamberbitter, implement proper cultural practices such as watering, mowing and feeding to make your yard less conducive to Chamberbitter establishment.
“Timing and persistence is important when dealing with chamberbitter because otherwise your efforts will not stop chamberbitter from repeatedly creeping up. Along with pre-emergent, it will help to put down a good thick mulch to help suppress chamberbitter from emerging. If Chamberbitter is already emerged, 2 4-D is your best option as it will kill the weed but not your grass”