Abies densa

Pinaceae Abies densa Griff.

Etymology
Abies refers to ‘to rise’; indicating large trees.
densa refers to the densely distributed needles.

Colloquial Name
Sikkim fir

Description
These trees can grow between 50 and 60 meters tall, with a trunk that remains straight, column-like, and unbranched at the base. The crown is broad and takes on a pyramidal or columnar shape when young, eventually flattening at the top in older trees. The bark starts off gray and smooth but quickly becomes scaly. As the tree ages, the bark near the base develops deep fissures and breaks into large plates.

The main branches are thick and long, spreading outward, with the upper ones angling slightly upward. The lower branches may droop over time. The smaller secondary branches also angle upward. The twigs are firm but relatively slender, except for the thicker leading shoots. They range in color from yellowish to reddish-brown when young, later turning gray. Their surface is prominently ridged and grooved, remaining mostly smooth but sometimes developing a fine fuzz in the grooves. The scars left by fallen leaves are rounded to oval in shape.

The buds are small, cone-shaped, and about 8 mm long. They are covered in sticky resin. Their outer scales are broad, rounded at the tip, and orange-brown in color, staying on the tree for several years before falling off. The needles are arranged in a spiral pattern, with most spreading out like a comb. On fast-growing and cone-bearing branches, they stand more upright, with the uppermost needles curving forward. They measure between 2 and 4 cm in length, sometimes reaching 5 cm, and are 1.5 to 2.5 mm wide. Their base is often twisted or curved. The needles are long and narrow, either straight or slightly curved, with a somewhat flattened shape. The edges curl under slightly. Their upper surface is a light or medium green, while the underside has two distinct white bands. The tips are usually notched. Stomata are arranged in two bands along the lower surface, separated by a green midrib.

The pollen cones grow along the branches in a radial pattern, meaning they are evenly spaced around the shoot rather than clustered on one side. They are 2 to 4.5 cm long and yellow, with small purplish-blue pollen-producing scales. The seed cones grow upright on short stalks or directly on the branches. They are cylindrical or sometimes slightly oval-shaped, with a rounded or slightly indented tip. When young, they are a deep purplish-blue color. As they mature, they turn a darker blackish-purple with some brown tones.

The cone scales are fan-shaped with a wedge-like base, measuring 1.5 to 2 cm long and 2 to 2.5 cm wide at the middle of the cone. Their surface is smooth or faintly ridged and has fine hairs on the exposed parts. The upper margin is unbroken and slightly curved inward, while the base narrows into a short stalk. The bracts inside the cone are oblong and spade-shaped, measuring 2 to 2.5 cm in length. They are either slightly visible or remain completely hidden inside the cone.

The seeds are wedge-shaped, about 8 mm long and 4 mm wide, with a brown color. Each seed has a broad, light brown wing that measures 10 mm long and 5 mm wide, helping it disperse in the wind.

Distribution

This map shows botanical records (points) for this taxon. By opening the map’s sidebar (collapsed by default) you can toggle visibility or change the basemap. By clicking on records, you reveal more information.

TDWG Codes
3, 36, CHT, 4, 40, ASS, ASS-AS, EHM, EHM-AP, EHM-BH, EHM-DJ, EHM-SI, NEP

Habitat
The natural habitats for Abies densa are temperate forests. It is naturally found at an elevation of at least 4000 up to 4000 metres. Other conifers associated with Abies densa are:

USDA Hardiness zone – 8
Abies densa is hardy to USDA Zone 8 (Bannister & Neuner, 2001), meaning its frost tolerance lies somewhere in the range of -12.2C (10F) to -6.7C (20F).

Species Continuity
The population trend for Abies densa is unknown. There are no known threats for Abies densa.

IUCN Category – LC
According to the IUCN Red List, Abies densa has been assigned the status of LC(Least Concern). This means that according to the Red List criteria, this species is not qualified as threatened.

Superordinate Taxa
The nearest superordinate taxon for Abies densa is Subsect. Delavayianae. The coordinate taxa for Abies densa are therefore:

Abies densa is further placed under Abietoideae. Abies densa is also placed under Pinaceae.

This map shows botanical records (points) for this taxon. By opening the map’s sidebar (collapsed by default) you can toggle visibility or change the basemap. By clicking on records, you reveal more information.