Dodecahema leptoceras

(A. Gray) Reveal & Hardham

Phytologia 66: 87. 1989.

IllustratedEndemicConservation concern
Basionym: Centrostegia leptoceras A. Gray Proc. Amer. Acad. Arts 8: 192. 1870
Synonyms: Chorizanthe leptoceras (A. Gray) S. Watson
Treatment appears in FNA Volume 5. Mentioned on page 474.
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Plants 0.3–0.8 (–1) × 0.2–0.8 dm. Leaf-blades (1–) 1.5–4 (–6) × 0.2–0.4 (–0.7) cm. Peduncles 0.5–1 mm. Flowers: perianth 1.2–1.8 (–2) mm; filaments 0.6–1 mm; anthers 0.4–0.5 mm. Achenes 1.7–2 mm. 2n = ca. 34.


Phenology: Flowering May–Jun.
Habitat: Sandy to gravelly flats and slopes, chaparral communities, pine-oak woodlands
Elevation: 200-700 m

Discussion

Of conservation concern.

Dodecahema leptoceras is known only from the foothills of the San Gabriel Mountains of Los Angeles County, the San Bernardino Mountains of San Bernardino County, and the San Jacinto Mountains of western Riverside County. The urbanization of the greater Los Angeles area has significantly reduced the number of known northern populations. Slender-horned spinyherb is federally listed as endangered.

Dodecahema leptoceras is in the Center for Plant Conservation’s National Collection of Endangered Plants.

Selected References

None.

Lower Taxa

None.

"/2" is not declared as a valid unit of measurement for this property."dm" is not declared as a valid unit of measurement for this property.

... more about "Dodecahema leptoceras"
dark-brown;black +
3-gonous +
red +  and maroon +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
James L. Reveal +
(A. Gray) Reveal & Hardham +
uncinate +
stipelike +
Centrostegia leptoceras +
awn-tipped +  and simple +
oblanceolate +
pubescent +  and glabrous +
lanceolate +
disarticulating +  and dichotomous +
not brittle +
just below the soil surface or and above the soil surface +  and spreading +
200-700 m +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
unisexual +  and bisexual +
disarticulating +  and solid +
decumbent to erect +  and prostrate +
unwinged +  and winged +
black +, red +, brown +  and yellowish +
exserted +  and included +
pubescent +  and glabrous +
spheroidal +, 4-gonous +, lenticular +, biconvex +, discoid +, 3-gonous +  and 2-gonous +
Sandy to gravelly flats and slopes, chaparral communities, pine-oak woodlands +
uniparous +  and cymose +
cymelike +, paniclelike +, racemelike +  and spikelike +
connate +  and free +
6-angled +, cylindric +  and tubular +
nonmembranous +
4 cm40 mm <br />0.04 m <br /> (6 cm60 mm <br />0.06 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (4 cm40 mm <br />0.04 m <br />) +
0.2cm;0.4cm +
in whorls +, opposite +, alternate +  and rosulate +
deciduous +
cauline +  and basal +
bractlike +
pubescent +  and glabrous +
lobed +, undulate +, crisped +, crenulate +  and entire +
not swollen +
orthotropous +
accrescent +
curved +  and straight +
erect to deflexed +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
cylindric +  and campanulate +
accrescent +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
fleshy +, indurate +  and membranous +
with extrafloral nectaries +  and not articulate +
Flowering May–Jun. +
homostylous +  and 3-carpellate +
, +  and solid +
slender;stout +
Illustrated +, Endemic +  and Conservation concern +
disarticulating +  and solid +
decumbent to spreading or erect +  and prostrate +
spreading +  and arising +
pubescent +  and glabrous +
not fistulose +
penicillate +, fimbriate +  and capitate +
deciduous +  and persistent +
2-lobed +  and cylindric +
coriaceous +  and membranous +
consisting of a series +  and tubular +
distinct +
erect;spreading or recurved +
spreading;erect +
Chorizanthe leptoceras +
chambered +, , +  and solid +
Dodecahema leptoceras +
Dodecahema +
species +
lobed +  and laciniate +
coriaceous +
persistent +
membranous +
pubescent +  and glabrous +
3 +, 2 +  and 1 +