It's not quite accurate to say trees grow *strictly* straight up. Most trees have some degree of branching and their trunks can curve slightly in response to wind, light, and other environmental factors. However, some trees are known for their generally upright, columnar growth habit. Here are a few examples:

Conifers:

* Redwoods (Sequoia sempervirens): These majestic giants are famous for their towering, straight trunks.

* Douglas fir (Pseudotsuga menziesii): Another tall conifer with a straight, columnar trunk.

* Norway spruce (Picea abies): This popular Christmas tree species has a symmetrical, conical shape.

* Cypress (Cupressus spp.): Many cypress species have a narrow, upright form.

* Cedar (Cedrus spp.): Cedars are known for their pyramidal shape, often with a straight central leader.

Deciduous Trees:

* Tulip poplar (Liriodendron tulipifera): This towering hardwood has a straight trunk and a tall, pyramidal crown.

* London plane tree (Platanus × acerifolia): This tree has a strong, upright trunk and a spreading crown.

* American elm (Ulmus americana): Before Dutch Elm Disease, American elms were known for their vase-shaped form with a straight, central trunk.

* Poplar (Populus spp.): Many poplar species have a fast-growing, columnar form.

Note: Even within these species, individual trees can vary in their growth habits depending on factors like genetics, soil conditions, and exposure to sunlight.