Leptarrhena

R. Brown

Chlor. Melvill., 15. 1823 ,.

Etymology: Greek leptos, slender, and arrhen, male, alluding to stamen filaments
Treatment appears in FNA Volume 8. Treatment on page 131. Mentioned on page 43, 45, 48, 132.
 TaxonIllustrator 
FNA8 P16 Astilbe biternata.jpegAstilbe
Astilbe biternata
Saxifragopsis
Saxifragopsis fragarioides
Leptarrhena
Leptarrhena pyrolifolia
Barbara Alongi
Barbara Alongi
Barbara Alongi
Barbara Alongi
Yevonn Wilson-Ramsey
Yevonn Wilson-Ramsey

Herbs rhizomatous, not stoloniferous; caudex scaly, not cormlike, with persistent leaf-bases. Flowering-stems ascending or erect, leafy, (8–) 15–35 (–48) cm, glabrous proximally, puberulent and stipitate-glandular distally. Leaves in basal rosette and cauline; basal leaves marcescent; cauline leaves 1–4, clasping, smaller distally; stipules inconspicuous, adnate to petiole; petiole absent in cauline leaves, present in basal, glabrous; blade obovate to elliptic, unlobed, base tapered, ultimate margins crenate-serrate, sometimes entire in cauline leaves, apex obtuse or rounded, surfaces glabrous or sparsely glandular abaxially; venation pinnate. Inflorescences compound cymes, terminal from terminal bud of rosette, (18–) 26–100-flowered, bracteate. Flowers: hypanthium adnate to proximal 1/4–1/2 of ovary, free portion absent, green proximally, usually purplish distally; sepals 5, greenish; petals 5, white; nectary disc absent; stamens 10; (anthers dehiscent by broad, terminal openings); filaments linear; ovary 1/4–1/2 inferior, 2-locular, carpels connate proximally; placentation axile; styles 2; stigmas 2. Capsules folliclelike, 2-beaked. Seeds yellowish-brown or tan, shiny, fusiform, ribbed (at least over embryo). x = 7.

Distribution

nw North America

Discussion

Species 1: nw North America.

R. J. Gornall (1985) reviewed the nomenclature of Leptarrhena. Based on molecular data, D. E. Soltis et al. (1993) placed it and the Asian, monospecific Tanakaea Franchet & Savatier sister in a group also including Boykinia, Jepsonia, Sullivantia, and Telesonix. Anther dehiscence in Leptarrhena and Tanakaea, which is by broad, terminal openings as opposed to longitudinal slits, appears to be unique in Saxifragaceae (H. G. A. Engler 1930). Soltis (1984d) found the karyotype of Leptarrhena to be distinct within the family.

Species 1

Selected References

None.

"full" is not a number.

... more about "Leptarrhena"
epigynous +, perigynous +  and hypogynous +
rounded +  and obtuse +
Craig C. Freeman +  and Richard K. Rabeler +
R. Brown +
tapered +
dentate +, serrate +  and entire +
glandular-ciliate +  and ciliate +
unlobed +, obovate +  and elliptic +
2-beaked +  and folliclelike +
3-carpellate +  and 2-carpellate +
nw North America +
Greek leptos, slender, and arrhen, male, alluding to stamen filaments +
unisexual +  and bisexual +
35 cm350 mm <br />0.35 m <br /> (48 cm480 mm <br />0.48 m <br />) +
15 cm150 mm <br />0.15 m <br /> (35 cm350 mm <br />0.35 m <br />) +
2-3(-4)-beaked +  and folliclelike +
multicellular +
bracteate +  and (18-)26-100-flowered +
opposite +  and alternate +
1/4 +  and 1/2 +
crassinucellate +, unitegmic +  and bitegmic +
epigynous +, perigynous +  and hypogynous +
distinct +
unlobed +  and lobed +
peltate +  and jointed +
unequal +
purplish +  and green +
Chlor. Melvill., +
tan +  and yellowish-brown +
straight +
muricate +, cellular-rugulose +, tuberculate +, pitted +, papillate +  and wrinkled +
fusiform +
distinct +
unbranched +  and branched +
persistent +
horizontal +  and erect +
inconspicuous +
connate +  and distinct +
glandular +  and glabrous +
Leptarrhena +
Saxifragaceae +
entire +  and crenate-serrate +
not stoloniferous +  and rhizomatous +
annual +, biennial +  and perennial +