perfoliata, t. 60 and Pulmonaria maritima, t. 368.
Striatus, striated, marked with fine parallel lines, as Oenanthe fistulosa, t. 363.
Sulcatus, furrowed, with deeper lines, as Smyrnium Olusatrum, t. 230.
Maculatus, spotted, as Hemlock, Conium maculatum, t. 1191.
The spines and prickles of the stem will be explained hereafter.
Internally the stem is either solidus, solid, as that of Inula crithmoides, t. 68, and numerous others; or cavus, hollow, as in Cineraria palustris, t. 151, as well as Hemlock, and many umbelliferous plants besides.
Plants destitute of a stem are called acaules, stemless, as Neottia acaulis, Exot. Bot. t. 105, and Carduus acaulis, Engl. Bot. t. 161. Such plants, when they belong to a genus or family generally furnished with stems, as in these instances and Carlina acaulis, Camer. Epit. 428, are liable from occasional luxuriance to acquire some degree of stem, but seldom otherwise. Pinguicula, Engl. Bot. t. 70 and 145, is a genus invariably stemless, while Primula, t. 4, 5, 6 and 513, is much