Dasylirion texanum

Scheele

Linnaea 23: 140. 1850.

Illustrated
Treatment appears in FNA Volume 26. Treatment on page 423. Mentioned on page 421, 422.

Plants typically small, with small crowns; trunks usually less than 0.5 m. Leaves narrow, arching gently downward, often twisting outward toward tip; blade usually shiny, bright green, 70–130 × 1–2 cm wide above broadened base, glabrous, not waxy, smooth; prickles mostly antrorse. Inflorescences 2–4 m; stalk 1.5–3 cm diam. at base; branches mostly basal, erect, 2.5–6 cm; bracts lanceolate; fascicles of flowers condensed, 5–8 cm from base to tip; primary-axes 0.5–1 cm. Flowers with receptacles ca. 0.2 mm; tepals whitish or greenish, 1.5 × 1 mm; style ca. 0.2 mm; stigma lobes 0.2–0.3 mm, loosely united; pedicel 2.2–3 mm in fruit. Capsules ellipsoid, 5.5–6 × 4–5 mm, distal wing lobes 1–1.5 mm, evenly rounded in cross-section, not indented. 2n = 38.


Phenology: Flowering May–Jul.
Habitat: Open, rocky limestone slopes, arroyos and canyons, dry limestone hills
Elevation: 600–1800 m

Discussion

Dasylirion texanum is often small, but can become quite large in moist situations. It is relatively homogeneous in the northeastern portion of its range in east-central Texas. In west Texas, plants are larger and have both antrorse and retrorse prickles. These have been included in D. heteracanthum I. M. Johnston, but they are probably hybrids between D. texanum and D. leiophyllum, in which the prickles are retrorse. There is little mixing of these two species except in a narrow zone extending northward through the Chisos, Davis, and Guadalupe mountains in west Texas.

Selected References

None.

Lower Taxa

None.

"broadened" is not a number.

... more about "Dasylirion texanum"
longitudinal +
glandular-pubescent +  and glandular +
David J. Bogler +
Scheele +
overlapping +
spoon--shaped +
expanded +
broadened +
bright green +
elliptic +, ovate +, oblanceolate +, lanceolate +  and linear +
not ceraceous +
1cm +  and 2cm +
stramineous +
reflexed +, erect +  and ascending +
lanceolate +
0.55 cm5.5 mm <br />0.0055 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
ellipsoid +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Tex. +  and Mexico (Coahuila) +
600–1800 m +
pubescent +  and glabrous +
female +, male +  and unisexual +
3-winged +  and capsular +
indehiscent +
fleshy +  and dry +
Open, rocky limestone slopes, arroyos and canyons, dry limestone hills +
racemose +  and paniculate +
200 cm2,000 mm <br />2 m <br /> (?) +  and 400 cm4,000 mm <br />4 m <br /> (?) +
persistent +
connate +
dentate +, serrulate +  and entire +
denticulate +
3-angled +
not +  and articulate +
0.22 cm2.2 mm <br />0.0022 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
semisucculent +
Flowering May–Jul. +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (?) +
0.2 cm2 mm <br />0.002 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
turbinate +  and 3-angled +
Illustrated +
exserted +  and included +
rudimentary +
aboveground +  and subterranean +
elongate +
0.2mm +  and 0.3mm +
3 +  and 1 +
exserted +  and included +
strap--shaped +
expanded +
0.2 cm2 mm <br />0.002 m <br /> (?) +
Dasylirion texanum +
Dasylirion +
species +
greenish;whitish +
distinct +
obovate +
reclining +  and erect +
0 cm0 mm <br />0 m <br /> (50 cm500 mm <br />0.5 m <br />) +
petal-like +
not indented +  and rounded +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +