Mirabilis melanotricha
Mirabilis multiflora
black-hair umbrellawort, four o'clock, mountain four-o'clock, Standley's four o'clock
Colorado four-o'clock, Froebel's four-o'clock, giant four o'clock
erect or strongly ascending, leafy mostly in proximal 2/3 of plant, openly forked distally, 5–12 dm, pubescent basally with minute curved hairs in 2 lines, spreading glandular-pilose distally.
4–7 dm.
ascending at 10–60°, progressively reduced toward infloresence;
petiole 0.8–3 cm;
blade bright green, narrowly triangular-ovate to ovate, 3–10 × 0.8–4 cm, ± thin, base acute, obtuse, truncate, or cordate, apex acute to attenuate, or obtuse, often rounded at tip, surfaces glabrous or rarely puberulent.
spreading;
petioles of proximal leaves 2–4 cm;
blades of midstem leaves ovate to widely ovate, sometimes suborbiculate, rarely reniform, 5–10 × 4–8 cm, base rounded to cordate, often asymmetric, apex acute or acuminate to obtuse, rarely rounded.
axillary and terminal, few branched, ± evenly forked and open;
peduncle 2–9 mm, spreading glandular-villous, crosswalls of hairs dark purple or black;
involucres blushed with dark violet or black, at least in median region, widely bell-shaped, 3–6 mm in flower, 4–7 mm in fruit, spreading viscid-villous, 40–50% connate, lobes oblong to ovate, apex broadly acute.
peduncle 4–75 mm;
involucres erect or ascending, 33–35 mm;
bracts 5, usually more than 50% connate, apex acute to obtuse or ovate.
3 per involucre;
perianth bright purple-pink, 0.9–1.2 cm.
6 per involucre;
perianth magenta, funnelform, 2.5–6 cm.
dark grayish to blackish brown, sometimes dark, dull, reddish brown, narrowly obovoid, 3–4 mm, spreading-pilose, hairs often apearing loosely shaggy and somewhat tufted, (0.1–)0.2–0.3 mm;
ribs ± same color as sulci, low and round, 0.7–1 times width of sulci, 0.5 times as wide as high, slightly rugose or warty;
sulci almost smooth to slightly rugose or with very low tubercules.
brown to black, with 10 slender, tan ribs alternating with 10 dark brown ribs, or ribs inconspicuous, ovoid or globose, 6–11 mm, smooth to rugulose, glabrous or pubescent, secreting mucilage or not when wetted.
= 66.
Mirabilis melanotricha
Mirabilis multiflora
The erect habit, bright green and usually glabrous foliage, and dark involucres of Mirabilis melanotricha are distinctive in combination. Once collected and pressed, M. melanotricha becomes yet another “difficult” Mirabilis. In 1911, P. C. Standley noted that this species (as Allionia melanotricha) was one of the most variable in the genus, and in 1918 he submerged it in A. comata, which in the field is a grayish green, clump-forming, glandular-pubescent plant with decumbent-ascending stems. Mirabilis melanotricha occurs in more mesic situations mostly at elevations above M. comata (here in synonymy in M. albida). It intergrades into M. linearis along its northern edge and lower elevations in New Mexico through M. linearis var. decipiens (Standley) S. L. Welsh. In the northeastern portion of its range, it may intergrade with M. nyctaginea; fruits in that region sometimes are slightly more reddish and more tuberculate than usual. Along the eastern portion of its range, it also intergrades into M. albida, as plants become more pubescent and fleshy. B. L. Turner (1993b) noted that M. comata (apparently in the sense of its common usage, as applied to plants here classified as M. melanotricha) might remain distinct from his concept of M. albida, which included C. F. Reed’s (1969) comprehensive M. oblongifolia.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Varieties 3 (3 in the flora).
G. E. Pilz (1978) recognized three partially sympatric varieties based on presence or absence of mucilage production in the fruits, fruit color, and apical acuteness of involucral bracts. Overall, populations are poorly differentiated, and in some areas plants represent a “collage” (Pilz’s term) that combine characteristics of different varieties; S. L. Welsh et al. (1987) recognized no varieties. Mirabilis multiflora is used in the Southwest in a minor way in xeriscapes. Among indigenous peoples, it has been used as food and medicine (V. L. Bohrer 1975; L. S. M. Curtin 1947).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Fruits tuberculate, mucilaginous when wetted; involucral bracts obtuse | var. glandulosa |
1. Fruits smooth to slightly tuberculate, not mucilaginous when wetted; involucral bracts acute | → 2 |
2. Fruits dark brown to black, ribs inconspicu- ous | var. multiflora |
2. Fruits light brown, with 10 slender, tan, longitudinal ribs alternating with 10 brown, often interrupted ribs. | var. pubescens |
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