fastigiate

adj

1. Erect and parallel.

   “The branches of this species are fastigiate.”

2. Having closely-bunched erect parallel branches

   “This is a fastigiate variety.”

3. Characterized by a fastigium, a cavity separating the intexine from the sexine near the endoaperture of a colporate pollen grain.

   “The grains are 3-colporate and fastigiate.”

4. (obsolete)Tapering to a point

   “We ascended the top of that noted hill, called Roseberry, or Ounsberry Topping, the top whereof is fastigiate, like a sugar-loaf, and serves for a sea-mark […]”

noun

1. A tree or shrub with erect, parallel branches.

   “An evening spent with a good catalogue or gardening encyclopaedia will reveal an astonishingly wide range of both weepers and fastigiates.”