Trimorphopetalum (Baker) Eb.Fisch.

Fischer, Eberhard & Rahelivololona, Marie Élisette, 2007, New taxa of Impatiens (Balsaminaceae) from Madagascar. V. New species of Impatiens from Masoala Peninsula, Adansonia (3) 29 (2), pp. 317-332 : 318-322

Subgenus Trimorphopetalum (Baker) Eb.Fisch.

DIAGNOSTIC CHARACTERS

Lower sepal without spur, extrafloral nectaries on petiole lacking.

A E H B

C

I

D F G

Impatiens ambanizanensis Eb.Fisch. & Raheliv. , sp. nov. ( Fig. 2 )

Impatiente salifii affinis sed ornamento sepali inferioris et petalibus lateralibus cum petalo superiore indistincte breviore quam petalo inferiore differt.

TYPUS. — Madagascar. Masoala, Ambanizana-Ambohitsitondroina, au pied d’Ambohitsitondroina vers 900 m, 19.II.2002, Rahelivololona, Saola & Scenario 145 (holo-, TAN).

DESCRIPTION

Perennial herb, with creeping rhizome entirely pubescent. Stem ascending to erect, up to 10-12 cm

tall. Leaves alternate, greenish with darker reddish veins, petiole 9-13 mm long, lamina ovate, 23-30 × 12-20 mm, margin crenate, with 4 or 5 pairs of teeth with a short gland-tipped appendage. Inflorescence with solitary axillary flowers. Pedicel up to 5-6 mm long, curved at apex, pubescent. Flower with greenish lateral sepals, petals entirely maroon. Lateral sepals lanceolate, pilose outside, 2-3 × 1 mm. Lower sepal navicular, broadly ovate, pilose outside, inside with distinct ornamentation, producing broad rib-like crests on the secondary nerves, 5-6 × 5 mm. Dorsal petal cucullate, pilose outside, 8 × 3.5 mm. Lateral united petals glabrous, 10 mm long, upper petal 5-6 × 1-1.5 mm, lower petal 7 × 4-4.5 mm. Anthers 3 mm long. Ovary 3 mm long. Fruit unknown.

REMARKS

Impatiens ambanizanensis is related to I. salifii Eb.Fisch. & Raheliv. from Masoala Peninsula, but differs in the ornamentation of the lower sepal producing broad rib-like crests on the secondary nerves (lower sepal with central ridge and 7 or 8 rib-like crests surrounding c. 7 holes on each side in I. salifii ) and the lateral united petals with upper petal only slightly shorter than lower petal (upper petal distinctly shorter in I. salifii ).

HABITAT

Montane rainforest at 900 m.

DISTRIBUTION

Madagascar, Masoala Peninsula, only known from the type collection.

Figures

FIG. 2. — Impatiens ambanizanensis Eb.Fisch. & Raheliv.: A, habit; B, C, flower; D, lateral sepal; E, F, lower sepal; G, dorsal petal; H, lateral united petals. Rahelivololona, Saola & Scenario 145 (TAN). Scale bars: A, 1 cm; B-H, 1 mm.