PlantFiles: Myrrh Gum
Commiphora myrrha

Biophysical limits
Altitude: 250-1300 m Mean annual rainfall: 230-300 mm Soil type: Prefers shallow soil, chiefly over limestone.

Botanic description
Commiphora myrrha is a sturdy, spiny, glabrous shrub or small tree, usually with a distinct short trunk up to 4 m tall. Outer bark silvery, whitish or bluish grey, peeling in large or small papery flakes from the greener under-bark; exudate hardly scented, viscid, producing a hard translucent yellowish gum-resin. All branches are spine tipped and knotted. Leaves trifoliate, chartaceous, greyish green or glaucous, very variable in shape and size; petiole 1-10 mm long; a few lateral leaflets, sometimes very minute may be found on both short and long and short shoot leaves, the leaves may be elliptic, spathulate or lanceolate, attenuate, cuneate, rounded or truncate at the base, rounded or acute apically, 6-44 mm long, 3-20 mm wide, with 3-4 rather weak main veins, margin entire or 6-toothed on each side. Male flowers usually precocious, 2-4 in dichasial cymes 3-4 mm long which are often sparsely glandular; bracteoles pale brown. 0.5-0.7 mm long and wide, often lightly attached at the base and forming a fragile detachable collar; receptacle beaker-shaped, petals oblong, tapering pointed and recurved at the tip, 4.5 mm long, 1.5 mm wide; filaments 1.4 and 1.2, anthers 1.2 and 1.0 mm long. Fruits 1-2 on jointed stalks, ovoid, flattened and beaked 2-4 mm long. Seed smooth with gentle swellings. C. myrrha is a very variable species, both in its leaves and in its pseudaril. The different forms seem to merge so impercetibly that the recognition of infraspecific taxa is often difficult. Forms in which the lateral leaflets are half as large as the terminal leaflet seem to occur only in the northern part of the area of the species and have not been seen in Kenya. The generic epithet is derived from Greek ‘kommis’ and ‘phora’ meaning gum bearer.