2. CERATELLA, Hook. fil.
Capitula aggregata, singulo 8–10-floro; floribus exterioribus sub 8, fœmineis, 1-serialibus; interioribus abortu masculis, omnibus, ut videtur, tubulosis. Involucrum 8–10-phyllum, squamis biserialibus coriaceis subacutis valde inæqualibus, interioribus linearibus 1–3-nerviis angustatis, exterioribus foliaceis latioribus plurinerviis, nervis omnibus cellulosis pellucidis transverse septatis. Receptaculum nudum, angustum, minutum, planiusculum vel subconicum, foveolatum. Fl. Fœm. Corolla tubulosa, elongata, basi globosa, ore profunde 4-dentato, dentibus majusculis subinæqualibus oblongis obtusis concavis medio macula oblonga pallida cellulosa pellucida deorsum in lineam extensa. Stylus validus, exsertus, basi bulbosus, apice breviter bifidus. Achænium compressum, tetragonum, anguste tetrapterum, alis membranaceis, oblongo-obovatum, 4-cornutum, cornubus brevibus divaricatis, 2 exterioribus sublongioribus. Fl. Masc. Corolla tubulosa, lineari-clavata, 3–4-dentata, sub 3–4-angulata, angulis pellucidis, dentibus concavis, dorso macula pellucida et linea extensa, ut in fl. fœm. Antheræ latiusculæ, inclusæ, basi breviter biaristatæ, apice apiculatæ, flavæ. Stylus validus, cylindraceus, corolla ⅓ brevior, apice sensim latiore abrupte truncato margine crenato. Achænium obscure 4-gonum, parvum, vacuum omnino calvum.—Herba pusilla, dense cæspitosa, Androsacis facie, rupibus præruptis ad cacumina montium insulæ Campbell proveniens. Folia alterna, densissime imbricata, stellatim patentia. Capitula aggregata, inter folia summa sessilia. Flores purpurascentes, parvi, inconspicui.
1. Ceratella rosulata, Hook. fil. (Tab. XVIII.)
Hab. Campbell's Island; in crevices of rocks at the tops of the mountains, at an elevation of 1400 feet; very sparingly.
Caules dense pulvinati, ramosi, duri, rigidi, 1–1½ unc. longi, validi, inferne foliis vetustioribus dense obsiti, fusco-nigrescentes. Folia arete imbricata, stellatim patentia, coriacea vel subcornea, superiora rosulata, basi latiore vaginante scariosa, medio contracta, deinde ovata, acuta, plus minusve concava, subtus striato-nervosa, marginibus acuentibus, superiora gradatim minora, 2–3 lin. longa, intense viridia, ætate fusco-tincta. Capitula in summos ramos 8–10, congesta, brevissime pedunculata, inconspicua, foliis subtensa, 2 lin. longa. Involucri squamæ irregulariter insertæ, ovato-oblongæ, subacutæ, concavæ, nervosæ, nervis (ut in Trineuro) celluloso-incrassatis transversim septatis pellucidis, interiores angustiores. Flores parvi, purpurei.
This plant is perhaps more closely allied to the last genus (Trineuron) than to any other, and exhibits many remarkable points of affinity with it, especially in the pellucid thickened parts of the flower and nerves of the involucral leaves; likewise the general structure of the capitula, corollas, stamens and styles is much alike in both. But while so many instances of resemblance exist, the totally different nature of the achænium becomes the more striking. In the tufted habit, harsh, coriaceous, even horny texture, the plant is more allied to Abrotanella emarginata.
These three genera form together a small group, allied in several respects to Hippia, Lessing, but naturally distinct, all the species of that division being herbaceous, more or less odorous, and often even furnished with pellucid glands.
The name is derived from the little horn-like processes of the achænium.
Plate XVIII. Fig. 1, a head of capitula; fig. 2, single capitulum, removed; fig. 3, receptacle and involucral scales; fig. 4, a flower of the ray; fig. 5, the same cut open; fig. 6, achænium; fig. 7, a 3-toothed flower of the disc; fig. 8, the same, with four teeth; fig. 9, the same cut open, and fig. 10, a stamen from do.:—all magnified.
3. LEPTINELLA, Cass.
Capitulum ∞ florum, heterogamum; floribus exterioribus fœmineis bi-triserialibus, disci abortu masculis tu-
