Pachysandra

Michaux

Fl. Bor.-Amer. 2: 177, plate 45. 1803.

Etymology: Greek pachys, stout, and pachys, man, alluding to thickness of staminal filaments
Treatment appears in FNA Volume 10.

Herbs or subshrubs, clonal; rhizomes branched, creeping, long. Leaves alternate, often crowded or fasciculate; blades margins dentate, surfaces dull or slightly shiny. Inflorescences from leafless nodes near base of stem or terminal [axillary], rarely from rhizomes, dense spikes [racemes]. Staminate flowers distal and, sometimes, 1 or 2 proximally; tepals 2 or 4; stamens exserted; pistillode absent. Pistillate flowers 1–7 per inflorescence, proximal, subtended by 7 or more scalelike bracts; tepals usually 4, sometimes more, white; ovary 2- or 3(or 4)-carpellate, apically 2 or 3-lobed; locules 1(or 2) per carpel; stigma linear, apical along inner surface of style; interstylar nectaries or nectariferous tissue absent; ovules 1 or 2 per locule. Fruits capsules or berries, ovoid to subglobose, dehiscence basal, circumscissile, glabrous or densely hairy. Seeds 1 per locule, brown or black, ovoid, 3-sided, smooth; carunculate or ecarunculate. x = 12.

Distribution

e, s North America, e Asia.

Discussion

Species 3 (2 in the flora).

The third species in the genus, Pachysandra axillaris Franchet, with two subspecies, axillaris and stylosa Boufford & Q. Y. Xiang, is intermediate between P. procumbens and P. terminalis in having axillary inflorescences. Similar to procumbens, axillaris has a 3-carpellate gynoecium; according to H. C. Robbins (1968), procumbens rarely has axillary inflorescences.

Selected References

None.

Key

1 Inflorescences from leafless nodes near base of stem or rarely from rhizome; ovaries (2 or)3(or 4)-carpellate; fruits capsules. Pachysandra procumbens
1 Inflorescences terminal on aerial shoots; ovaries 2(or 3)-carpellate; fruits berries. Pachysandra terminalis