OCR Text |
Show 350 PHYSIOGNOMY OF PLANTS. by ramification properly so called. Lichtenstein, in his 11 Reisen im siidlichen Africa" (th. i. s. 370), gives a vivid description of the impression made upon him by the appearance of a Euphorbia officinarum which he found in the 11 Chamtoos Rivier," in the Colony of the Cape of Good Hope ; the form of the tree was so symmetrical that the candelabrum-like arrangement was regularly repeated on a smaller scale in each of the subdivisions of the larger branches, up to 32 English feet high. All the branches were armed with sharp spines. Palms, Yuccas, Aloes, tall-stemmed Ferns, some Aralias, and the Theophrasta where I have seen it growing luxuriantly, different as . they are in the structure of their flowers, yet offer to the eye in the nakedness (absence of_ branches) of their stems, and in the ornamental character of their tops or crowns, a certain degree of physiognomic resemblance. The melanoselinum decipiens (Hofm.) which is sometimes upwards of 10 or 12 feet high, and which has been introduced into our gardens from Madeira, belongs to a peculiar group of arborescent umbelliferous plants, to which Araliacere are otherwise allied, and with which other plants, which will doubtless be discovered in course of time, will be associated. Ferula, Heracleum, and Thapsia, do indeed attain a considerable height, but they are still herbaceous plants. Melanoselinum is still almost entirely alone as an umbelliferous :tree; Bupleurum (Tenonia) fruticosum (Linn.) of the shores of the Mediterranean; Bubon galbanum of the Cape, and Crithmum maritimum of our sea-shores, are only shrubs. On the other hand, the tropical zone, in which, according to the old and very just remark of Adanson, Umbelliferre and Cruciferre are almost enti;rely wanting in the plains, presented to us on the high ridges of the American Andes, the smallest and most dwarf-like of all umbelliferous plants. Among 38 species of plants which we collected at elevations where the mean temperature is below 10° Reaumur (54° .5 Fah.), there vegetates almost like mosses, and as if they made part of the rock and of the often frozen earth, at an elevation of 12,600 (13,430 English) feet above the level of the sea, Myrrhis andicola, Fragosa arctioi:des, and Pectophytum pedunculare, intermingled with which there is an equally dwarfed Alpine Draba. |