This tree is fast-growing, but not very long-lived by pine standards (to 200 years).
It reaches heights of 18–30 m (59–98 ft) with a trunk diameter of 0.6–0.8 m (2.0–2.6 ft).
The leaves are needle-like, very slender, in clusters of two or three, and are 18–24 cm (7.1–9.4 in) long.
The cones are glossy red-brown, 5–15 cm (2.0–5.9 in) in length with a short (2–3 mm or 0.079–0.118 in), thick prickle on each scale.
It is known for its conical shape.

It may be distinguished from the related loblolly pine (Pinus taeda) by the somewhat longer, glossier needles and larger red-brown cones, and from longleaf pine (Pinus palustris) by the shorter, more slender needles and smaller cones with less broad scales.

There are two described varieties of Pinus elliotii.
However, recent genetic studies have indicated that the varieties may not be more closely related to each other than they are to other pines in the Southeast.
If this is the case, re-classifying these varieties as separate species would be warranted.
Slash pine (Pinus elliottii) can hybridize with loblolly pine (Pinus taeda), sand pine (Pinus clausa), and long leaf pine (Pinus palustris).

The two commonly accepted varieties are the following:
P. elliottii var.
elliottii (typical slash pine) which ranges from South Carolina to Louisiana, and down to Central Florida.
Its leaves are in bundles, fascicles of twos and threes, mostly threes, and the cones are larger, 7–15 cm (2.8–5.9 in).

P. elliottii var.
densa (South Florida slash pine, Dade County pine) is found in the pine rocklands of Southern Florida and Florida Keys, including the Everglades.
 Leaves are nearly all in bundles of two with longer needles.
The cones are smaller, 5–12 cm (2.0–4.7 in), the wood is denser, and the tree has a thicker taproot.
Unlike the typical variety of slash pine, seedlings of P. elliottii var.
densa has a "grass stage," similar to longleaf pine.
P. elliottii var.
densa is not frost tolerant which limits its range to South Florida.
This tree is fast-growing, but not very long-lived by pine standards (to 200 years). It reaches heights of 18–30 m (59–98 ft) with a trunk diameter of 0.6–0.8 m (2.0–2.6 ft). The leaves are needle-like, very slender, in clusters of two or three, and are 18–24 cm (7.1–9.4 in) long. The cones are glossy red-brown, 5–15 cm (2.0–5.9 in) in length with a short (2–3 mm or 0.079–0.118 in), thick prickle on each scale. It is known for its conical shape.
It may be distinguished from the related loblolly pine (Pinus taeda) by the somewhat longer, glossier needles and larger red-brown cones, and from longleaf pine (Pinus palustris) by the shorter, more slender needles and smaller cones with less broad scales.
There are two described varieties of Pinus elliotii. However, recent genetic studies have indicated that the varieties may not be more closely related to each other than they are to other pines in the Southeast. If this is the case, re-classifying these varieties as separate species would be warranted. Slash pine (Pinus elliottii) can hybridize with loblolly pine (Pinus taeda), sand pine (Pinus clausa), and long leaf pine (Pinus palustris).
The two commonly accepted varieties are the following:
P. elliottii var. elliottii (typical slash pine) which ranges from South Carolina to Louisiana, and down to Central Florida. Its leaves are in bundles, fascicles of twos and threes, mostly threes, and the cones are larger, 7–15 cm (2.8–5.9 in).
P. elliottii var. densa (South Florida slash pine, Dade County pine) is found in the pine rocklands of Southern Florida and Florida Keys, including the Everglades.  Leaves are nearly all in bundles of two with longer needles. The cones are smaller, 5–12 cm (2.0–4.7 in), the wood is denser, and the tree has a thicker taproot. Unlike the typical variety of slash pine, seedlings of P. elliottii var. densa has a "grass stage," similar to longleaf pine. P. elliottii var. densa is not frost tolerant which limits its range to South Florida.
Pinus elliottii