Dudleya nesiotica

(Moran) Moran

Leafl. W. Bot. 7: 110. 1953,.

EndemicConservation concern
Basionym: Hasseanthus nesioticus Moran Desert Pl. Life 22: 99, figs. 5–7. 1951
Treatment appears in FNA Volume 8. Treatment on page 194. Mentioned on page 173, 192.

Corms subglobose to irregular, 1–3 cm × 7–20 mm. Leaves 8–16; petiole 1–4(–7) mm wide, to 1/3 as wide as blade; blade green, linear-oblanceolate to spatulate, 2.5–3.5(–5) cm × 3–15(–25) mm, 2–5 mm thick, base 4–12 mm wide, apex acute to obtuse, surfaces sometimes glaucous. Inflorescences: cincinni 3–8-flowered, 2–4 cm; floral shoots 3–10 cm × 1–3 mm (slightly thicker distally); leaves 15–25, spreading, blade triangular-lanceolate to -ovate, 1–2.5 cm × 5–10 mm, 3–6 mm thick, apex subacute to obtuse. Flowers with musky, sweet odor; petals connate 1–2 mm, erect or spreading, white, yellowish green on keel and toward base, not lined, elliptic, 7–14 × 3.5–5.5 mm, apex acute, corolla 4–5 mm diam. at base and 5–18 mm diam. at apex; pistils connivent or separate, erect at anthesis; ovary 4–7 mm; styles 1–1.5 mm. Follicles ascending, with adaxial margins ca. 45–75º above horizontal. 2n = 68.


Phenology: Flowering late spring.
Habitat: Heavy soil on flats near sea
Elevation: 10-30 m

Discussion

Of conservation concern.

Dudleya nesiotica is known from the west end of Santa Cruz Island, where it is abundant, and it is considered seriously threatened (California Native Plant Society, http://cnps.web.aplus.net/cgi-bin/inv/inventory.cgi). It resembles D. blochmaniae in its white petals and especially in its floral odor. It differs from other species of subg. Hasseanthus and approaches subg. Dudleya in its larger and more-erect petals and its more-erect pistils. The first collection had rosette leaves broader than in other species, not only in the blade but also in the petiolar region and at the base. These facts together with the chromosome number suggested that D. nesiotica might be an allotetraploid of D. blochmaniae, or a relative, and some member of subg. Dudleya (R. V. Moran 1951). However, some later-found plants of D. nesiotica have the leaves much narrower, in fact linear-oblanceolate, as shown by S. Junak et al. (1995). M. Dodero (1996) considered subg. Hasseanthus monophyletic and thought D. nesiotica most closely related to its near neighbor D. blochmaniae subsp. insularis on Santa Rosa Island 10 kilometers to the west, with which it shares four allozyme characters. D. Wilken (pers. comm.) has found mostly linear leaves in D. nesiotica of open sites but great variation in leaf shape in plants from denser vegetation.

Dudleya nesiotica is in the Center for Plant Conservation’s National Collection of Endangered Plants.

Selected References

None.

Lower Taxa

None.