Neomarica gracilis or walking iris has sword like leaves.
Opposite arrangement
Iris can get bacterial leaf blight, fungal leaf spot, fungal crown rot, iris borers, aphids, verbena bud moths, crickets and wood lice.
alternate
Two
Ivy plants have alternate leaf arrangement, which means that leaves are arranged along the stem in an alternating pattern. Each leaf grows in a staggered formation rather than directly across from each other.
single
Leaf veins.
alternate
Yes, an iris is considered a monocot plant. Monocots have seeds with only one cotyledon (seed leaf) and typically have parallel veined leaves, and the iris fits these characteristics.
whorled Being a member of the family Lamiaceae, basil leaf has opposite arrangement
A walking leaf, also known as a leaf insect, looks like a dried leaf with vein-like markings on its body. It has evolved to mimic a real leaf as a form of camouflage to evade predators. When moving, it may sway back and forth to mimic the motion of a leaf blowing in the wind.
Shagbark Hickory has an alternate leaf arrangement.