Dudleya traskiae

(Rose) Moran

Desert. Pl. Life 14: 153. 1942 (as traskae) ,.

Common names: Santa Barbara Island dudleya
EndemicConservation concern
Basionym: Stylophyllum traskiae Rose in N. L. Britton and J. N. Rose, New N. Amer. Crassul., 34. 1903 (as traskae)
Synonyms: Echeveria traskiae (Rose) A. Berger
Treatment appears in FNA Volume 8. Treatment on page 177. Mentioned on page 173, 174.
Revision as of 12:01, 30 July 2020 by imported>Volume Importer
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Caudices to 2 dm × 1–3 cm, clumps to 5 dm diam. Leaves without resinous odor; rosette 25–40-leaved, 10–20 cm diam.; blade light green, oblong to oblong-oblanceolate, flat, usually channelled adaxially, 4–15 × 1–4 cm, 2.5–6 mm thick, 4–6 times wider than thick, base 10–40 mm wide, surfaces mostly farinose, not viscid, not oily. Inflorescences: cyme 2–3-branched, obpyramidal, (2–3 × 0.5–2 dm); branches 1–2 times bifurcate (sometimes with some scattered proximally); cincinni 7–20-flowered, somewhat circinate, 4–12 cm; floral shoots 2–5 dm × 3–8 mm; leaves 20–45, spreading to slightly ascending, triangular-ovate, 1–4 × 1–1.5 cm. Pedicels 1–3 mm. Flowers: petals ascending near base and outcurved, connate 1–2 mm, bright-yellow, elliptic or narrowly ovate, 8–10.5 × 3–4 mm, apex acute, corolla 5–6 mm diam. at base and 8–15 mm at apex; pistils suberect, 7–10 mm; styles 2.5–4 mm. Follicles ascending, slightly gibbous adaxially, beaks ascending to spreading. 2n = 68.


Phenology: Flowering spring.
Habitat: Sheer cliffs and rocky slopes
Elevation: 0-100 m

Discussion

Of conservation concern.

Dudleya traskiae is endemic to Santa Barbara Island. It was once thought exterminated by feral rabbits (R. N. Philbrick 1972); the rabbits have been removed and the plants survive (R. V. Moran 1978), recovering on the slopes and in fact probably always secure on the sheer sea cliffs. According to R. Clark and W. L. Halvorson (1987), it is making a good recovery.

The campanulate corolla of Dudleya traskiae is intermediate between the prismatic or tubular corolla of subg. Dudleya and the open corolla more typical of subg. Stylophyllum and found in all the diploid species, including the most primitive. The corolla is much like those of hybrids between members of the two subgenera, and D. traskiae is tetraploid. These two facts together suggest that the species may have arisen as an amphidiploid hybrid (R. V. Moran 1978).

Selected References

None.

Lower Taxa

None.
... more about "Dudleya traskiae"
perigynous +  and hypogynous +
Reid V. Moran +
(Rose) Moran +
2.5mm +  and 6mm +
wider +  and thick +
Stylophyllum traskiae +
ascending +  and spreading +
light green +
lobed +  and toothed +
distal +, terete +  and laminar +
oblong +  and oblong-oblanceolate +
1 cm10 mm <br />0.01 m <br /> (4 cm40 mm <br />0.04 m <br />) +
1-2 times bifurcate +
elongate +
whorled +, opposite +  and alternate +
4 cm40 mm <br />0.04 m <br /> (12 cm120 mm <br />0.12 m <br />) +
Santa Barbara Island dudleya +
0.5 cm5 mm <br />0.005 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
2-3-branched +
obpyramidal +
0-100 m +
0.3 cm3 mm <br />0.003 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
branched +  and simple +
ascending;spreading +
erect;spreading +
Sheer cliffs and rocky slopes +
axillary +  and terminal +
sessile +, petiolate +  and subclasping +
alternate +  and crowded +
persistent +
1 cm10 mm <br />0.01 m <br /> (4 cm40 mm <br />0.04 m <br />) +
spreading +  and slightly ascending +
triangular-ovate +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
wider than tall +
semi-inferior +  and superior +
tenuinucellate +, crassinucellate +  and bitegmic +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
perigynous +  and hypogynous +
bright-yellow +
8mm;10.5mm +
ovate +, elliptic +  and outcurved +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Flowering spring. +
(3-)4-5(-12)[-30+]-carpellate +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
Desert. Pl. Life +
cross-ribbed +  and ribbed +
1 +  and many +
Endemic +  and Conservation concern +
adnate +  and free +
antipetalous +
2-branched +  and simple +
distinct +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
not oily +  and not viscid +
Echeveria traskiae +
Dudleya traskiae +
Dudleya subg. Stylophyllum +
species +
cylindric +  and 5-gonal +
perennial +, biennial +  and annual +