Microtea maypurensis
Content
Description
Erect to decumbent herb to 50 cm tall. Stem slender, glabrous, angular, suberect. Leaves lanceolate or linear-lanceolate, rarely elliptic-lanceolate, ca. 3.5 x 0.3-1 cm, acute at apex and base, glabrous; petiole ca. 1 cm long. Inflorescence a terminal, rarely axillary, pedunculate, elongate, suberect raceme to 10 cm long; pedicels ca. 1.5 mm long; bracts lanceolate, ca. 0.8 mm long, acute; bracteoles linear-subulate, ca. 0.3 mm long, inserted at base of pedicel. Tepals elliptical, ca. 1.5 mm long, acute, with green midvein; stamens 6-9, anthers ca. 0.2 mm wide; ovary ca. 0.5 mm, stigmas 3(5-6)-partite, ca. 0.2 mm. Achenes exceeding tepals, black, globose, ca. 1.5 mm, acute, echinulate in a honeycomb pattern, spinelets glochidiate, with recurved apex and 4 retrorse apical bristles.
Distribution
Guianas present, tropical South America present
Tropical South America; 26 collections studied, 8 from the Guianas (GU: 5; SU: 3).
Notes
Differences between the two Microtea species are most evident under magnification (see ). The reticulate (honeycomb, waffle) pattern on the fruit of M. debilis exhibits protuberances which are very pale brown or cream, chartaceous, often irregularly bent or crisped, non-glochidiate at the apex, and to 0.2 mm long. By contrast, the (superficially) similar pattern on the fruit of M. maypurensis exhibits protuberances which are dark brown, hard (or at least stiff-looking), straight, glochidiate with 4 minute bristles at the apex, and to 0.5 mm long. The apex of the barb-like protuberance is provided with 4 retrorse, acicular bristles ca. 0.1 mm long, and an inner set of even shorter bristles. In addition, leaves from near the base or middle of the plant of M. maypurensis are often linear or narrowly elliptical, 0.3-1 cm wide, whereas leaves of the common M. debilis are usually wider (to 3 cm wide).