Page:The Botany of the Antarctic Voyage.djvu/55

 two plants is the same, and both are natives of Pacific Islands, abounding in peculiarly inclement localities; the present being an inhabitant of the Antarctic regions, while the Argyroxyphium is found only on the summits of the highest mountains on the Sandwich Islands. Mr. Douglas brought it from the volcano of Mouna Kaah, which reaches an altitude of 18,400 feet, where it was one of the last plants he met with, and he used its dead stems for fuel. In the clothing and substance (as far as can be judged from dry specimens) of the stem, in the disposition of the inflorescence and form of the involucral scales, and in the short ligul&aelig; of the flowers of the ray, these plants entirely accord: and the lower leaves of the latter, though uniform in size and shape with the upper, and having the margins quite entire, are always clothed with a similar but more beautiful and dense silky coat of hairs. On a further examination of the form of the corollas and ach&aelig;nia the analogy ceases. It must not however be overlooked, that the pappus of Pleurophyllum, though composed of set&aelig; (and not of short pale&aelig;), is of a peculiarly harsh and rigid texture, with each seta flattened and scabrid on the opposite margins, quite unlike the soft character that organ assumes in most Composit&aelig;, both showing its affinity to other Asteroide&aelig;, and some approach to the short rigid pale&aelig; of the Sandwich Island plant. Although the Argyroxyphium is placed by DeCandolle in Senecionid&aelig;, its styles appear to me to differ in no important particular from those of the Pleurophyllum and of other large Asteroid genera. In both these, the styles of the flowers of the ray are always longer than those of the disc, with the arms also longer, linear, obtuse and flattened, erect or diverging in most of the tribe, divaricated and inclined to become revolute in Argyroxyphium; they are invariably quite smooth throughout, and surrounded with a thickened darker-coloured border (the stigmatic series), those of the corresponding side of each arm meeting at the base. In the flowers of the disc they are shorter, equally bordered with a thick conspicuous margin, abruptly ceasing at the commencement of a conical, acute, rather broader apex, which is plane and smooth, or most indistinctly glandular, on the inner surface, but with the margins and convex back densely studded with elongated papill&aelig; or glands (the pollen collectors); these papill&aelig;, except under a very high power, appear as hairs: the arms have further a strong opake central nerve in each, meeting and uniting at the base. In Argyroxyphium the conical apices are very short and studded with long papill&aelig;, whence they appear abrupt, and each of the arms is split into two parallel lamin&aelig;, between which a knife is easily inserted, when the midrib is seen remaining on the inner of the two lamell&aelig;, and the stigmatic series on the outer. I do not think that in a natural system the two genera now under consideration should be far separated from one another, or from the following genus Celmisia, Cass.

Though generally so very bulky a plant, that an ordinary specimen of the Pl. criniferum weighs many pounds, I have seen it so dwarfish upon the mountains as barely to exceed a span in height, with all the leaves lanceolate, more densely silky, and thus even more nearly resembling Argyroxyphium than it does in its ordinary state. The masses of curly fibres, which may be taken up in handfulls from the summit of the roots of a common-sized plant, form a very remarkable character.

XXIV. & XXV. Fig. 1, receptacle and portion of involucre with flower of ray and disc in situ; fig. 2, single scale of the involucre; fig. 3, alveol&aelig; of the receptacle; fig. 4, set&aelig; of the pappus; fig. 5, a corolla with the ligula 3-partite; fig. 6, a flower of the ray with the ligula 3-toothed; fig. 7, style from the same; fig. 8, front, and fig. 9, lateral view of the ach&aelig;nium; fig. 10, flower of the disc; fig. 11, corolla of do.; fig. 12, stamen, and fig. 13, style from do.:—all magnified.   

Capitulum multiflorum, heterogamum; floribus radii 1-serialibus, ligulatis, f&oelig;mineis; disci numerosis, tubulosis, hermaphroditis, 5-dentatis. Involucrum campanulatum, v. depresso-hemisph&aelig;ricum, pluriseriale, squamis elongatis in&aelig;qualibus disco paulo longioribus v. sub&aelig;quilongis. Receptaculum nudum aut alveolatum, epaleaceum, latiusculum, plus minusve convexum. . Corolla tubo elongato terete glaberrimo v. piloso pilis articulatis; ligula lineari, patente, interdum revoluta, apice subintegra v. 3-dentata, albida, s&aelig;pius roseo suffusa. Stylus teres, gracilis, exsertus, ramis linearibus plus minusve elongatis obtusis v. subacutis, marginibus valde