Hedeoma hispida Pursh - Mock Pennyroyal

Hedeoma hispida plant

Family - Lamiaceae

Stems - To 20cm tall, simple, from fibrous roots, herbaceous, 4-angled, tomentose to hirsute, multiple from base, fragrant (slightly).

Hedeoma hispida stem

Leaves - Opposite, decussate, linear to linear-oblong, to 2cm long, 3mm broad, entire, punctate, stigillose and ciliate-margined, sessile, fragrant (slightly).

Hedeoma hispida leaves

Inflorescence - Vertcillasters of 8 flowers(4 at each leaf base). Pedicels to +2mm long, hirsute. Flowers subtended by 2-6 linear bracts. Bracts 6-7mm long, pubescent, ciliate-margined.

Flowers - Corolla bilabiate, purplish-blue, pubescent, to 5mm long. Stamens 2, adnate 1/2 way up corolla tube. Filaments purple. Anthers yellow, .2mm broad. Style purple, 2.3mm long, slightly exserted from upper lip or included. Ovary 4 parted, (4 nutlets). Nutlets (in flower) glabrous, purplish, .1mm long. Calyx bilabiate, hirsute to hispid. Calyx tube to 3mm long, 12 to 13-nerved, swollen below near base, floccose internally by lobes, otherwise glabrous internally. Upper lip 3 lobed. Lobes attenuate, 1.1mm long, ciliate-margined. Lower lip 2-lobed. Lobes linear-attenuate, 2.2mm long, ciliate-margined.

Hedeoma hispida calyxCalyx close-up.

Hedeoma hispida corollaCorolla.

Flowering - May - July.

Habitat - Prairies, glades, sandy open ground, roadsides, railroads.

Origin - Native to U.S.

Other info. - Although this plant is common throughout the entire state of Missouri, it is frequently overlooked because of its small size. The flowers are striking but minute and often missed.
The species is easy to ID in the field because of its small size and densely hairy stems and calices. The leaves of the stem are really nothing more than foliaceous bracts as the plant begins to flower very early in its life cycle. The lowest flowers of the plant are cleistogamous and have minute to absent corollas.

Photographs taken off Lee Rd 27, Auburn, AL., 5-11-05.


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