Growing and Using Native in the Northern Interior of B.C. parviflora Dougl.exLindl. small-flowered blue-eyed Mary Family:

Figure 97. Documented range of in northern British Columbia.

Figure 98. A dense stand of Collinsia parviflora plants that voluntarily emerged from the seed bank of an old hay field after it was cultivated.

 Symbios Research & Restoration 2003 135 Growing and Using Native Plants in the Northern Interior of B.C. Collinsia parviflora Dougl.exLindl. small-flowered blue-eyed Mary (continued)

Background Information

Collinsia parviflora is an annual (the only one treated in this manual), found north to Alaska and southern Yukon, east to Ontario, and south to Pennsylvania, Michigan, South Dakota, New Mexico, Arizona and California. It is common in B.C., except in the northeast (Douglas et al. 2000).

Growth Form: Annual herb from a tap root; opposite smooth or minutely hairy leaves, purplish underneath; terminal cluster of short-stalked flowers, 2 lipped; the upper flower lip is two-lobed, white; the lower flower lip is three-lobbed, blue; mature size is 5 - 50 cm tall (Douglas et al. 2000).

Site Preferences: Moist to dry grassy slopes, mossy rock outcrops, forest glades and open forests at low to middle elevations (Douglas et al. 2000). In coastal B.C. it is reported to be shade-intolerant, found on very dry to moderately dry nitrogen-medium soils, including open forests on very shallow soils (rock outcrops and cliffs) and meadow-like communities on water-shedding sites. This species is considered characteristic of moisture-deficient sites, and its occurrence appears to increase with increasing temperature (Klinka et al. 1989). Collinsia parviflora tolerates a minimum of 406 mm and a maximum of 1270 mm of annual precipitation; it can tolerate minimum temperatures to -36oC (NRCS 2002).

Seed Information Seed Size: Length: 1.64 mm (1.22 - 1.94 mm) Width: 1.12 mm (0.84 - 1.40 mm) Seeds per gram: 1,174 (range: 904 - 1,449) Volume to Weight Conversion: 758.3 g/L at 87.9% purity Germination Capacity: At 30o/20o C untreated: not tested At 25o/15o C untreated: 24.9% (3 - 49%). stratified: 5.0% (2–8%). Germination Speed: No data available. Seed Longevity: Unknown; probably quite long, Figure 99. Seeds of Collinsia parviflora. as it has emerged from the seed bank of agricultural Rule divisions are 1.0 mm. soils maintained in hay production for decades.

Considerations for Growing Techniques for Seed Production Seed treatment: Stratification apparently inhibits germination, at least under cool conditions. Stand establishment: Requires loamy, well-prepared soils, firm seedbed; site should be free of all weeds, especially rhizomatous grasses because selective herbicides cannot be used once plants are growing; sow early in the year as seeds seem to germinate better under cool conditions. Row spacing: Unknown; suggest 75-120 cm under dryland conditions, 30-90 cm under irrigation. Seeding density: Unknown at present; suggest 60-100 PLS per linear metre (Smith and Smith 2000).

136  Symbios Research & Restoration 2003 Growing and Using Native Plants in the Northern Interior of B.C. Collinsia parviflora Dougl.exLindl. small-flowered blue-eyed Mary (continued)

(Techniques for Seed Production, continued)

Seeding depth: Surface to shallow seeding; a light dusting of peat moss will help to keep the seeds in place. This species may be slow to establish from seed, as its dormancy mechanism appears to be complex; establishment from greenhouse-propagated plugs may be more reliable, though will be relatively expensive relative to seed yield because propagation has to be repeated annually. Stand maintenance: Regularly cultivate rows and spot spray with herbicide to keep plot weed free. Since this is an annual species, plots should be retilled annually. If any seed drops before harvesting (which is highly likely), the same plot can often be used year after year for Collinsia seed production. Response to fertilization is unknown.

Harvesting and Seed Processing: The date of selective harvesting in the Bulkley Valley of northwestern B.C. have been as early as July 30th. Seed heads of this species shatter moderately easily, dehiscing when ripe. Hand clipping: Use sharp hand clippers. Hold the seed heads over bins placed alongside the plants being clipped or place a bag over the seed heads before clipping to minimize seed loss. Do not allow seed capsules to become over ripe or they will dehisce before harvest and you will lose many seeds. Plastic between rows is recommended so dehisced seeds can be salvaged. Vacuum: Suitability unknown at present. Seed stripper: Suitability unknown at present. Combine/thresher settings: 1850 rpm with a 1-2 mm gap. Seed cleaning: After threshing, run a through fanning mill using the following screen configurations: prescreen 1.8 x 12.7 mm; top screen 1.2 x 7.1 mm; bottom screen 1.2 mm square. Run through vacuum separator at medium suction to remove dust and chaff. Storage requirements: Cool dry conditions, though seeds of this species are apparently tolerant of a wide range of environmental conditions.

Considerations for Use in Revegetation • Collinsia parviflora has higher germination at lower temperatures, so late fall or early spring sowing is recommended. • Collinsia parviflora has possible use as a cover crop, because this annual species grows quickly, flowers early, and has shallow roots that can provide green-up and erosion control with minimal competition with perennial species. Emergence has been spotty in field trials, however, indicating that we do not fully understand the dormancy mechanisms in the seed of this species. • Until we can better utilize its properties as an annual, inclusion of this species in a seed mixture is generally for diversity, and for its long-lived seeds that may be important constituents of the seed bank at some time in the future.

Other considerations: • Collinsia parviflora has a delicate blue flower that grows easily, so this species has possible ornamental value.

 Symbios Research & Restoration 2003 137 Growing and Using Native Plants in the Northern Interior of B.C. Collinsia parviflora Dougl.exLindl. small-flowered blue-eyed Mary (continued)

Notes

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