- elainahanzel
- 6 hours ago
- 3 min read
Though its foliage appears shadowy among fragmented rock landscapes, Veronica densifolia's blooms are like painterly drifts reminiscent of remnant snow. Both morphological traits express the dynamic processes inherant to native alpine plant communities.
Subtly emerging from schist and granite crevices, this diminutive plant is almost imperceptible, the petite leaves nearly indiscernible among otherwise tawny and weathered terrain, but for its solitary purple buds and palest lilac blossoms. Native Veronica densifolia (commonly hebejeebie, or snow hebe in Australia) inhabits subalpine-alpine environments (1150-1830m), fellfield (stable rock-strewn landscapes dominated by low plants above the timberline, among such snow), bluffs and outcrops, damp crevices in rock tors and outcrops, and moist peaty hollows or seepage sites in the South Island.
A recumbent subshrub, it navigates these craggy surfaces on woody horizontal stems, with numerous minute branches ascending no more than 5mm high in a trailing mat-like habit. The olivey-brown, even rust-coloured foliage can be glabrous or pubescent, but is importantly composed of imbricate (overlapping), tightly appressed lance-shaped or narrowly ovate leaves. The interior of each leaf exhibits discernible concave curvature with fleshy recurved margins. The arrangement of leaves, and the trichomes more common on the leaf exteriors, are morphological adaptations to trap heat and reduce transpiration and desiccation against high winds, uv exposure, and frost. Adapted to such unstable and impoverished soils, it is sensitive to humidity and also drought, but receives moisture in the microhabitats created by fractured, eroded rock. Prostrate and shying away in these niches, it is protected from the most abrasive conditions and competition from denser vegetation.
The single, sessile (attached to the stem) flower is more reminiscent of the oft-maligned Oxalis (false shamrock) than New Zealand's more typical Veronica (formerly Hebe) species which bear profuse racemes. This is a notable distinction from genera, including Veronica, occurring at lower elevations, which display greater colour and inflorescence diversity. In alpine plant communities, flowers are most typically white or yellow and possess an almost disproportionate open, bowl-shaped corolla as pollination occurs primarily by hymenopteran insects during the short alpine summers. This is further characterised by non-specialist flies (syrphids), native moths, beetles, and small solitary bees, rather than long-tongued social bees or bird species, providing an important food resource in the South Island's high-altitude pollinator networks.
A flowering period of November-January aligns with seasonal snowmelt, providing necessary moisture during the plant's energy-intensive reproductive processes. Fruits emerge January-March, but may persist throughout the year. Seed dispersal for the ensuing hygrochastic capsules is characterised by minor ballistic projection in response to water and sometimes wind, opening only during rainfall events and usually in nearby micro-niches, allowing for successful germination and colonization of growing areas.
Hybridisation has rarely been observed, but includes V. densifolia x V. thomsonii (V. uniflora Kirk). Veronica densifolia exhibiting triffid leaves suggests hybridization with V. trifida. Of more familiar species, it is most like parahebe (Veronica lyalli) a tender perennial shrub of the subalpine region, but well adapted to most New Zealand gardens. Low-growing and compact, it displays similarly sprightly white flowers with violet-pink nectar guides that persist summer through autumn. It prefers well-drained but evenly moist soils in sun or light shade.
Though evidently slightly mighty and currently listed "not-threatened" among such a challenging terrain, the species is susceptible to physical habitat disturbance and species competition (invasive). Such introduced flowering species may make native alpine pollinator-plant dynamics vulnerable to the integration of non-native pollination mutualists.
This Veronica and and other alpine species are also vulnerable to climate change as altered snowmelt reduces appropriate habitat and germination capability.
