Lobelia spicata Lam.

Spiked Lobelia


CC = 5
CW = 0
MOC = 82

© DETenaglia

Family - Campanulaceae

Habit - Perennial forb with fibrous roots.

Stems - Ascending to erect, to 80 cm, simple, usually unbranched (occasionally with a few branches near the base), narrowly winged, longitudinally angled, glabrous or sparsely to moderately pubescent with short, curved to more or less spreading hairs mostly toward the base.

Lobelia_spicata_stem.jpg Stem and node.

© SRTurner

Leaves - Alternate, simple, sessile, predominating toward base of plant and gradually reduced above the stem base. Leaf blades 1-7 cm long, 1.0-2.5 cm wide, obovate to oblanceolate, narrowly oblong, or lanceolate, the base strongly decurrent below the attachment point as a pair of wings of green tissue along the stem, rounded or angled to a bluntly pointed tip, the margins entire or less commonly with sparse, irregular teeth, also usually with short, fine, spreading hairs, the surfaces glabrous or with sparse hairs.

Lobelia_spicata_leaves1.jpg Lower leaves.

© SRTurner

Lobelia_spicata_leaf1.jpg Leaf adaxial.

© SRTurner

Lobelia_spicata_leaves.jpg Pressed leaves.

© DETenaglia

Inflorescence - Terminal, densely to loosely flowered spikelike racemes, the axis glabrous or sparsely hairy, the lowermost bracts lanceolate, the upper bracts much shorter and more or less linear, each flower also with a pair of minute bracts immediately below the calyx.

Lobelia_spicata_inflorescence1.jpg Inflorescence.

© SRTurner

Lobelia_spicata_inflorescence2.jpg Inflorescence detail.

© SRTurner

Flowers - Resupinate. Calyces 4-7 mm long, the tube 0.5-1.5 mm long at flowering, not becoming inflated as the fruit matures, the slender lobes 3-5 mm long, often with auricles 0.2-1.5 mm long. Corollas strongly zygomorphic and bilabiate, 4-10 mm long, pale blue or white, the tube 3-5 mm long, not slitted, the lobes 2-5 mm long, the lower lip with a beard of dense hairs on the inner surface toward the base. Stamens 5, adnate at base of corolla tube. Filament tube 2.3-3.5 mm long, the anther tube 1.4-2.0 mm long. Anthers purplish-blue, connate around stigma. Stigma purple, bearded at base. Style 1, 5 mm long, glabrous, greenish. Ovary ovoid-conic, slightly compressed, green, 2-locular. Placentation axile.

Lobelia_spicata_flowers.jpg Flowers.

© SRTurner

Lobelia_spicata_calyx.jpg Calyx.

© SRTurner

Lobelia_spicata_flower.jpg Flower.

© DETenaglia

Lobelia_spicata_flower2.jpg Lateral view.

© DETenaglia

Fruits - Capsules 3.5-5.0 mm long. Seeds 0.4-0.8 mm long, ovoid to ellipsoid, the surface with a series of minute pits and ridges, reddish brown.

Flowering - April - August.

Habitat - Prairies, glades, savannas, ledges and tops of bluffs, forest openings, streambanks, fens, pastures, fields, railroads, roadsides, open disturbed areas.

Origin - Native to the U.S.


Other info. - This variable species is found throughout Missouri, as well as most of the eastern half of the continental U.S. It is easily recognized by its erect, narrow inflorescences of distinctively shaped flowers. The flowers are resupinate, positioned on the inflorescence in an upside-down orientation. The flowers can be bluish to white, crowded or sparse on the inflorescence, the stems can be glabrous to hispid, and the calyx lobes can have variable auricles at their bases. Yatskievych reluctantly recognized two phases of the plant in Missouri, var. leptostachys and var. spicata, based mostly on subtle differences in the calyces.

Photographs taken at the Peck Ranch Wildlife Refuge, Carter County, MO., 7-12-03 (DETenaglia); also at Taum Sauk State Park, Iron County, MO, 7-11-2013, and Onondaga Cave State Park, Crawford County, MO, 6-25-2014 (SRTurner).