Art. LIX.—Notes on Panax lineare, Hook., f.
[Read before the Wellington Philosophical Society, 29th July, 1876.]
During a recent botanical excursion in the Waimakiriri District, Mr. J. D. Enys and myself were greatly interested in collecting, at altitudes below 4,000 feet, a number of plants, hitherto supposed to be restricted to the extreme south-western portion of the Colony, or to the Auckland Islands:— Donatia novæ zealandiæ, Drosera stenopetala, Gaimardia celiata, G. setacea, Lyperanthus antarcticus, Panax lineare, etc.
Panax lineare was observed in several localities, and a good series of specimens collected, elucidating the changes it undergoes before it reaches maturity. The interest attached to this species, from its remarkable character and great rarity, has induced me to draw up the following description, which supplies a few omissions in the diagnosis given in the “Handbook to the New Zealand Flora,”
Panax lineare, Hook., f.
A small, sparingly branched, diæcious shrub, 5–8 feet high, ultimate branchlets very short and crowded. Leaves in the young state 6–3 inches long, ½′ ⅓′ wide, crowded, ascending, simple, coriaceous, linear, acute, apiculate, gradually narrowed into a short broad petiole, midrib stout, prominent above, margins thickened, distantly serrate; gradually passing into the mature leaves, which are crowded at the ends of the branchelets, intermixed with numerous hard, coriaceous, subulate scales with membranous margins, spreading, linear-lanceolate, acute, or obtuse, margins thickened, finely and distantly serrate, midrib flattened above, keeled below; petiole very short and stout, not jointed. Flowers in terminal umbels, sessile or very shortly peduncled; male umbels shorter than the leaves, of from 4–6 spreading bracteolate, 5–6 flowered rays, calyx teeth minute, ovate; female umbels smaller, shortly peduncled, of from 3–7 or more simple, 1–3 flowered rays; fruit ovoid, elongated; styles 5, connate for one-third of their length, the upper portion free and recurved.
The description in the Handbook was drawn from two small specimens collected by Lyall in Chalky Bay in 1848; Hector and Buchanan collected it in Dusky Bay in 1863. It appears to have escaped further notice until observed by Mr. Enys and the writer, in January last, not far from the Waimakiriri Glacier, and in several spots in Bealey George, altitude 2,500 to 3,000 feet. The herbarium of the Colonial Museum contains a small specimen recently collected on Mount Cook by Mr. McKay, of the Geological Survey Department.
In the diminished size and alteration of form which characterize the
leaves, as this plant approaches maturity, it resembles P. crassifolium, Den. and Planch., but differs from that species in the ascending position of the leaves in their young state, and in their uniformly simple character at all ages. In these respects, it also resembles an undescribed species discovered by Dr. Hector and myself near Nelson, and for which I have proposed the MS. name of P. ferox, while it approaches it closely in the linear and entire character of the mature leaves.
An abnormal specimen collected by Mr. Buchanan in Dusky Bay, and now in the Otago Museum, has the mature leaves ovate, much broader than those of the typical form, and with the midrib less prominent. Another specimen exhibits a sessile male umbel with 16 or 17 rays.
In habit and appearance Panax lineare closely resembles the simple-leaved form of Solanum laciniatum when growing in exposed situations.