"Clump forming herbaceous plant.  Pseudostem to 4 m. tall, 28 cm. diam. near the base.  Predominantly brown with dead clinging [leafbases] otherwise green with some dark brown coloration in the upper parts, no wax ; undersheath cream to white, juice milky white or creamy.  Suckering moderate, arising alongside or up to 20 cm. from parent, erect or nearly so.  Sucker leaves mostly auriculate.   Shoulder brown or green, entire, smooth and appressed, without any scarious margin.   Fourth last leaf 242 x 88 cm., right handed to c. 8 mm., (almost symmetrical), the base cordate to weakly auriculate.  Other leaves often left-handed and predominantly strongly auriculate, all green, hardly different in colour above and below, slightly paler beneath and with the prominent midrib, mostly pale yellow, sometimes with a little brown proximally without obvious wax.  Petiole 52 x 4.5 cm., the adaxial channel green, open with only slightly incurved or erect margins which are green, not or only narrowly (to c. 1 mm.) scarious, abaxially the petiole dark chocolate brown TS ratio 0.78 (see Argent 1976). PB ratio 4 - 5.

Peduncle stout, green, glabrous, densely scarred.   Bunch horizontal, diagonal or occasionally held completely vertically downwards.   The female bracts lanceolate to 54 x 12 cm., yellow, shiny outside, dull yellow and slightly paler inside, acuminate the apical 12 cm. with the margins strongly inrolled, completely and quickly deciduous.  Female flowers with a few staminodes mostly less than half the length of the style, free tepal flushed purple.  Ovary trilocular, each locule with the ovules in two rows.

Male peduncle growing vertically downwards.  The male bud up to 14 x 11 cm., shiny yellow imbricate for c. 2 cm. from the tip.  Male bracts 13 x 7 cm., shiny rich yellow outside, slightly darker near the margins, the tips pale green, shiny yellow inside although becoming dull inside after falling, with broadly rounded, obtuse apices, lifting to a high angle c. 45° to the axis ; after falling only recurved at the base not revolute from the apex or margins.  Male flowers, two-rowed, falling in a group, cream, the free tepal translucent white, with a rounded, erose upper margin and no wrinkle, just over half as long as the compound tepal.  Compound tepal cream with pale yellow apices, the two longest points with irregular papillose to subdenticulate margins.

Fruit bunch dense, sub-spherical in shape to 17 x 18 cm.  Fruit two-rowed, the second hand with 14 fruits.  The fruits irregular, apparently ageotropic as they show no curvature in any part of the bunch, ripening orange but the surface becoming mostly blackish by full maturity, 8 - 9 x 2.5 - 3.5 cm., 3-, 4- or 5-angled, broadly truncate at the apex with large scars up to 2 cm. diam., splitting irregularly to reveal pale pinkish orange pith and similarly coloured or yellowish flesh around the seeds in the carpel chambers, the pith white at the base of the fruit ; yellow latex exuding from the cut skin of the immature fruit.  Pedicel c. 2 - 3 mm, the fruits almost sessile.  Seeds dark brown, 4 - 5 mm. diam., irregular with rounded angles and with a distinctly domed boss opposite the hilum which is c. 2 mm. in diam. and vertically striate, also with a raised band on one side from hilum to boss."

(Argent 2001).

Musa johnsii is one of only six bananas currently known in which the fruit splits (or dehisces or is schizocarpic) on maturity, the others are Musa hirta from Borneo, Musa velutina from India, Musa lolodensis and Musa schizocarpa from Papua New Guinea, and Musella lasiocarpa from China and northern Indo-China.

Images:

There are two images of M. johnsii.