Elsholtzieae

Northern horsebalm Collinsonia canadensis, copyright Michael Hough.

Belongs within: Lamiaceae.

The Elsholtzieae are a group of herbs and shrubs with an asymmetric floral disc and globose nutlets (Harley et al. 2004).

Characters (from Harley et al. 2004): Annual or perennial herbs or shrubs. Stems often four-angled. Leaves opposite, usually petiolate. Inflorescence usually an often secund raceme-like thyrse or panicle of 1(-3)-flowered cymes in the axils of usually much reduced bracts, sometimes conspicuous, broad, imbricate, often venose, bracteoles usually absent. Calyx ± 10-lobed, five-nerved (3/2), often more or less actinomorphic at anthesis, usually accrescent in fruit and usually becoming more distinctly two-lipped, corolla ± 2-lipped, 4-5-lobed (1-2/3), lobes usually with short, scarcely spreading lobes, posterior lip 1-2-lobed, anterior lip 3-lobed, corolla-tube often short. Stamens 4 or 2 by reduction, often exserted, weakly didynamous, divergent, filaments glabrous, anthers 2-thecous, thecae parallel to divergent, separate or apically confluent. Style with two usually equal, subulate stigma-lobes. Disc asymmetrical with anterior lobe elongate. Nutlets usually globose, sometimes reduced to one by abortion, smooth, reticulate or foveolate, abscission-scar very small, often circular.

<==Elsholtzieae
    |--Elsholtzia O88
    |    |--E. densa O88
    |    |--E. eriostachya O88
    |    |--E. fruticosa O88
    |    `--E. strobilifera O88
    `--Collinsonia Linnaeus 1753 [incl. Keiskea Miquel 1865] HPR03
         |--*C. canadensis HPR03
         |--C. australis (Wu & Li) Harley in Harley, Paton & Ryding 2003 [=Keiskea australis Wu & Li 1977] HPR03
         |--C. elsholtzioides (Merr.) Harley in Harley, Paton & Ryding 2003 [=Keiskea elsholtzioides Merr. 1937] HPR03
         |--C. glandulosa (Wu) Harley in Harley, Paton & Ryding 2003 [=Keiskea glandulosa Wu 1965] HPR03
         |--C. japonica (Miquel) Harley in Harley, Paton & Ryding 2003 [=*Keiskea japonica Miquel 1865] HPR03
         |--C. macrobracteata (Masam.) Harley in Harley, Paton & Ryding 2003 [=Keiskea macrobracteata Masam. 1940] HPR03
         |--C. sinensis (Diels) Harley in Harley, Paton & Ryding 2003 [=Keiskea sinensis Diels 1924] HPR03
         `--C. szechuanensis (Wu) Harley in Harley, Paton & Ryding 2003 [=Keiskea szechuanensis Wu 1965] HPR03

*Type species of generic name indicated

REFERENCES

Harley, R. M., S. Atkins, A. L. Budantsev, P. D. Cantino, B. J. Conn, R. Grayer, M. M. Harley, R. de Kok, T. Krestovskaja, R. Morales, A. J. Paton, O. Ryding & T. Upson. 2004. Labiatae. In: Kadereit, J. W. (ed.) The Families and Genera of Vascular Plants vol. 7. Flowering plants. Dicotyledons. Lamiales (except Acanthaceae, including Avicenniaceae) pp. 167-275. Springer.

[HPR03] Harley, R. M., A. J. Paton & O. Ryding. 2003. New synonymy and taxonomic changes in the Labiatae. Kew Bulletin 58: 485-489.

[O88] Ohba, H. 1988. The alpine flora of the Nepal Himalayas: An introductory note. In The Himalayan Plants vol. 1 (H. Ohba & S. B. Malla, eds) The University Museum, University of Tokyo, Bulletin 31: 19-46.