Waltheria lundelliana J.G. Saunders
Descripción
Heterostylous shrubs 1-3 m tall with clustered branches spreading from base, arching downward from tips; secondary branches, inflorescences and leaves distichous; all plant parts external to the petals densely puberulent with trichome radii 0.1-0.2 mm long unless other- wise noted. Leafy stems densely and minutely stellate-tomentose, becoming glabrescent; bark dull grayish brown. Leaves gradually reduced along inflorescence branch; leaf blades ovate, 3.5-12.5 cm long, 2.0-6.3 cm wide, acute apically, obtuse to rounded basally, with margins resin-tipped dentate and plicate, with adaxial surface grayish green, densely and minutely stellate-tomentose, trichome radii to 0.1 mm long, with abaxial surface minutely stellate-canescent, with trichome radii to 0.2 mm long; petioles 0.4-2.7 cm long, 1.0-1.3 mm wide, bearing 6-8 longitudinal ridges, with sparse over- lying trichome layer to 0.3 mm long; stipules 1.6-5.0 mm long, 0.4-1.0 mm wide. Inflorescences of axillary, secund, compacted cymes to 2 cm long bearing 30-60 flowers, with stalks 0.5-1.0 cm long; primary flowering unit consisting of 2 sessile flowers with 4 distinct bracts at base; bracts 4, 3.3-5.2 mm long, 0.5-1.0 mm wide, stellate-tomentose (radii to 0.1 mm long), with overlying sericeous layer of simple trichomes to 0.7 mm long adaxially, and marginally. Thrum flowers 2.5-3.5 mm in diameter; calyces 3.8-5.5 mm long, 2.0-2.5 mm wide, stellate-tomentose, with trichome radii 0.1-0.2 mm long, with overlying stellate-sericeous layer, with trichome radii 0.4-0.7 mm long; calyx tubes 3.0-3.6 mm long, 2.0-2.5 mm wide; calyx lobes triangular, 1.6-2.0 mm long, acute at tip; corollas yellow, rarely red-orange, petals spatulate, eciliate, 3.2-4.8 mm long, 0.8-1.5 mm wide, emarginate or rounded apically; stamens 4.0- 5.5 mm long; stamen tube 0.5-1.2 mm long; free filaments 3.0-4.6 mm long; anthers 0.7-1.2 mm long, 0.4-0.5 mm wide; pistil 3.4-3.8 mm long; ovary 0.7-1.2 mm long, 0.5-0.8 mm wide, sericeous apically, with trichome radii 0.5-0.7 mm long; style 1.5-2.5 mm long, lateral, densely stellate-tomentose throughout (radii to 0.2 mm long); stigma clavate, 0.5-0.9 mm long, 0.3-0.5 mm wide, with dense stigmatic branches to 0.2 mm long. Pin flowers similar to thrum flowers except stamens 2.0-3.8 mm long, free filaments 1.0-2.0 mm long, pistil (3.5-probably an abberant individual) 5.2-5.8 mm long, style (2.3- probably an abberant individual) 3.7-4.2 mm long, sparsely stellate-pubescent at base, (radii to 0.1 mm long); stigma clavate, 0.6-1.0 mm long, 0.5-0.7 mm wide, with branches 0.2-0.3 mm long. Fruit an obovoid capsule, 2.1-2.7 mm long, 1.5-2.0 mm wide, with partial loculicidal dehiscence. Seed reddish brown, 1.8-2.1 mm long, 1.2-1.5 mm wide, obovoid, rounded at apex, testa verrucate with irregular sinuous ridges or bumps.
Pollen. Thrum: spinulose, spines not very dense, apertures 5-6 (average 5.9 for N = 76), zonoporate, colpus index 10.45, 44.7 um long x 53.2 um wide, P/E = 0.84, ora 4.37 um long x 4.37 um wide (with annulus) (N = 25 for Saunders 1810 and Saunders 1812); pin: reticulate, apertures 4-5 (average 4.9 for N = 87), colpus index 1.93, 40.3 um long x 41.2 um wide, P/E = 0.98, colpus 21.12 um long, 1.5 um wide, ora 5.4 um long x 6.96 um wide, (N = 25 for Saunders 1818 and Saunders 1803).A
Pollen. Thrum: spinulose, spines not very dense, apertures 5-6 (average 5.9 for N = 76), zonoporate, colpus index 10.45, 44.7 um long x 53.2 um wide, P/E = 0.84, ora 4.37 um long x 4.37 um wide (with annulus) (N = 25 for Saunders 1810 and Saunders 1812); pin: reticulate, apertures 4-5 (average 4.9 for N = 87), colpus index 1.93, 40.3 um long x 41.2 um wide, P/E = 0.98, colpus 21.12 um long, 1.5 um wide, ora 5.4 um long x 6.96 um wide, (N = 25 for Saunders 1818 and Saunders 1803).A
Distribución
México (país) EndémicoA
Elevación
370 mA
Ecología y Hábitat
Seems to be a local endemic, restricted to the western side of the low mountain range just west of Milpillas and Compostela in the state of Nayarit. It occurs on steep slopes of rocky outcrops, with thin soil, on rocky grassy glades and open forest understory on limestone substrate with Byrsonima, Quercus, Bixa, Curatella and Ceiba in subdeciduous tropical forest.A
Tipo de vegetación
Pastizal de otro tipo, Selva bajaA
Categoría IUCN
No incluidaB
Categoría NOM-059-SEMARNAT-2010
No incluidaC