SOME CRITICAL SPECIES OF ECHIUM. 365 
gineum, pomponium, pustulatum, pyrenaicum, rubrum, tuberculatum, and 
vulgare seem to behave as annuals or biennials, according to circumstances. 
In December, 1917, I was able to observe carefully large numbers of 
italicum, pyrenaicum, plantagineum, and pustulatum around Rome and near 
Taranto. In every case I found that the plant which had flowered in the 
summer was a dead skeleton with a rotten root. There were no living plants 
of any of those species, except baby seedlings, which would undoubtedly 
flower and perish in their turn within 12 months. But in cultivation, and 
in climates with a less prolonged summer drought, the evidence seems to 
point to a biennial habit, with two possible flowering seasons. /chium 
angustifolium, Mill., on the other hand, appears to have taken the opposite 
course, for whilst Miller grew it as an annual at Chelsea, we are assured by 
Haláesy that in Greece it (Z. elegans) is perennial. 
The presence of hairs on the filaments, an excellent distinctive character 
for one or two species, has been made too much of by de Coincy for certain 
others, in which the hairs are very obscure and very few, and not constantly 
present. On the other hand, he has perhaps underrated differences in the 
nueules, whieh serve to separate true vulgare from its southern substitutes, 
The size of the corolla can only be used with reservation as a specific 
character, for in most, if not all, the species, sexual variation affects the size, 
sometimes to an extreme degree, as in so-called Æ. Wierzbickii and in the 
pistillate form of Æ. setosum, Vahl. Colour is more reliable, but dangerous 
to depend on in dried specimens, especially if these have been exposed to the 
action of any acid. And it is to be borne in mind that the blue kinds often 
throw white or pink individuals. 
Echium rubrum stands by itself on account of its undivided style with 
a capitate stigma. It is strange that this character should not have been 
noticed by Jacquin himself or by De Candolle in the * Prodromus. It would 
be an exaggeration to create a new monotypic genus on this ground, but it 
necessitates some modification of the received generic definitions of chium. 
De Candolle, Prodr. x. p. 16, says: “ stigma bipartitum, stylo nempe apice 
bilobo, lobis filiformibus " ; the accurate Bentham, in Gen. PI. ii. p. 863, 
“stylus filiformis, apice breviter 2-fidus, stigmatibus parvis." —Gürke in 
Engler’s * Pflanzenfamilien,’ iv. 3, p. 128, merely translates Bentham's Latin 
into German, without addition or subtraetion of a syllable. 
In the course of my researches I have seen all the specimens of the genus 
in the following herbaria, besides my own :— 
]. Kew. 
2. British Museum. 
3. Sibthorp’s, Sherard’s, and Dillenius’s plants at Oxford. 
4. The Bailey herbarium now in the Museum of Manchester Uni- 
versity. 
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