This is a simple technique, nothing special, it maybe works for one task but not for another. So feel free to improve, or change the technique as you like, to get the result you want. Also you will need to be familiar with max, I will not explain where the different tools are or how they work.
First draw a simple three point "Spline" in the front or left view as shown in the picture. Keep in mind to close the spline other wise it will not work correctly. Also don't click and drag since that produces a bezier spline, we want a linear spline.
Now go into sub-object mode, select all points, right click on one of the selected points to get into the quad menu and set them to be "Bezier Corner" rather than "Corner". If you don't do that you will later not get enough subdivisions for bending the spline.
Since we wanna use the max own scatter function we need to take care of the pivot. We want it to be at the bottom of the grass shaft. Normally we could use the adjust pivot tools but for objects we want to use with scatter there appears to be a bug; it will never use the pivot you have set, it will always use the original pivot that was created when you made the spline. So what we do is go out of sub-object mode and see where the pivot is at the moment, keep the position in mind or place a dummy at this position, go back into sub-object mode and move the vertex selection so the bottom of the shaft is at the same location as the pivot. Leave sub-object mode, check that the pivot is in the correct position. If so then go onto the next step.
Add a "Bend" modifier to the shape and set it to "Angle": 60.0, "Direction": 90.0 "Bend Axis": Y Also alter the center position in the sub-object mode so that the lower part of the shaft is parallel to the viewport grid. You can use different values if you like, it's up to you. They mean nothing. I just picked them because they produce a good result.
Put an "Editmesh" on top, just to generate the mesh and add also a "UVW" modifier on top of it. Try to align the UVW gizmo to the overall shape of the shaft to avoid the texture getting stretched. Simply do this by rotating the gizmo in sub-object mode. You can also use the Center, Fit or Align function in the modifier to make it more easy.
Clone the mesh and hide the copy. This is just if you wanna change something and don't wanna redo it all again from the start or you maybe want to do other versions of shaft bended with different values. Ok now add a material to it, I'm not going to go into any depth with that, just a simple "2 Sided", green coloured material will do the trick for now. If you feel like you need to add something more complicated go ahead. Small note, something you should use for a grass material is translucency to give it a more realistic look. Since the material structure of grass allows light to shine thru the shaft and be visible on the other site, same for shadows that are casted onto the grass, they are also visible on the opposite side.
Collapse the stack so we get a "Editable Mesh" or "Editable Poly" and now add "Scatter" to it. Scatter can be found in the create menu under "Compound Objects". Now we also need a distribution object where we want the grass to "grow" on. Create a "Plane" from the top or perspective view. Give it some more sub-divisions like 20x20. Add a basic brown-green coloured material to it.