Staurogyne repens (Nees) Kuntze (1891: 497)

Braz, Denise Monte & Monteiro, Reinaldo, 2017, Taxonomic Revision of Staurogyne (Nelsonioideae, Acanthaceae) in the Neotropics, Phytotaxa 296 (1), pp. 1-40 : 27-28

19. Staurogyne repens (Nees) Kuntze (1891: 497) . Ebermaiera repens Nees von Esenbeck (1847: 20) . Lectotype (designated by Braz & Monteiro 2011b: 176): — BRAZIL. Mato Grosso: Cuiabá, June 1827, L. Riedel1087 (lectotype: LE!). ( Fig. 18 )

Creeping herb, densely branched, floral branches somewhat erect, with simple dense trichomes, scattered at the base. Leaves sessile or with a petiole up to 3 mm long; blade ovate-lanceolate, 0.9 − 5.3 × 0.3 − 0.7 cm, apex acute, base acute to obtuse, adaxially glabrescent, abaxially with sparse simple trichomes restricted to the veins. Inflorescence in lax, terminal and axillary, bracteate spike, 1.2 − 7.3 cm long, terminal ones sessile, axillary ones with peduncle 2 − 3.4 cm long; flowers opposite at the base, alternate above; rachis, bracts and bracteoles sparsely simple and glandular pilose; bracts and bracteoles green, not-ciliate, bract elliptic to slightly oblong, 4.3 − 8 × 1.4 − 3.6 mm, 1 − 3-nerved, bracteoles lanceolate to linear-lanceolate, 3.2 − 5.2 × 0.7 − 0.9 mm. Flowers sessile to subsessile; calyx green, pilose with sparse simple and glandular trichomes, non-ciliate, posterior segment 3.8 − 7 × 0.7 − 1.6 mm, 3-nerved, lateral pair of segments 3 − 5.5 × 0.3 − 0.6 mm, anterior pair of segments 3.5 − 5.5 × 0.5 − 0.7 mm; corolla white with vinaceous markings at limb and throat, 4.8 − 7.8 mm long, basal tube 1.5 − 2.3 mm long, anterior lobe 1.8 − 2.8 mm long, externally with sparse simple trichomes, internally glabrous; posterior stamens 0.9 − 2.3 mm long, anterior stamens 1 − 2.7 mm long, staminode 0.3 − 0.7 mm long; ovules 19 − 20 per locule, posterior lobe of the stigma divided to deep-concave. Capsule not found.

Specimens examined:— BRAZIL. Amazonas: São Gabriel da Cachoeira , 1 August 1852, Spruce 2212 ( BM, BR, E, K, P) ; São Gabriel da Cachoeira, March 1852, Muer 2212 ( P). Mato Grosso: Cuiabá, June 1827, Riedel 1 ( LE).Pará: 13 November 1907, Guedes s.n. (MG-2291). Without locality: s.d., Jansen s.n. (E-116844) .

Distribution and habitat:— Staurogyne repens is a Brazilian Amazon species, occurring in humid areas under the forest canopy.

Phenology:— It was collected with flowers between August and October.

Taxonomic notes:— Staurogyne repens is characterized by its creeping branched habit, with floriferous erect branches, leaves ovate-lanceolate, sparsely hairy to glabrescent, the long terminal and axillary spikes and the infundibular corolla with scattered simple trichomes externally. It resembles Staurogyne spraguei and S. miqueliana , both also Amazon species, but it differs from S. spraguei especially by the habit densely (not sparsely) branched, the spikes 1.2 − 7.3 cm long (not up to 2.3 cm long) and the corolla pilose (not glabrous), and from S. miqueliana by the glabrescent (not hairy) leaves, the petal-like (not leafy-bracteate) inflorescence and the corolla 4.8 − 7.8 mm long (not 3.8 − 5.1 mm). Based on the analysis of the several herbaria collections studied, materials of S. repens are scarce and the last collection was recorded in 1907, which indicates that its natural occurrence is very rare or even that the species could be extinct. However, due to its preferred habitat by wet environments, it has been largely cultivated as an aquarium or ponds borders plant, requiring special methods for submerged cultivation (http://www.tropica.com/en/ plants/plant-articles/staurogyne-repens.aspx).

Figures

FIGURE 18. Staurogyne repens.A.Flowering plant. B. Flower, bract and bracteoles. C. Bract. D. Bracteoles.E. Calyx. F.Anther in frontal view. G. Anther in dorsal view. H. Staminode. I. Stigma in lateral view. J. Corolla lobes. (A, E–J from Vieira & Castro 288; B–D from Cavalcante et al. 1978).